minor fix
[oweals/gnunet.git] / src / sensor / gnunet-service-sensor.c
index b11da6ecd0129e324e7513e694b313a8fd616091..4dc366cc15e668cc39de74bf382fc9911c742910 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 
+     (C)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
 #include "platform.h"
 #include "gnunet_util_lib.h"
 #include "sensor.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_peerstore_service.h"
 
 /**
- * Minimum sensor execution interval (in seconds)
- */
-#define MIN_INTERVAL 30
-
-/**
- * Structure containing sensor definition
+ * Our configuration.
  */
-struct SensorInfo
-{
-
-  /*
-   * Sensor name
-   */
-  char *name;
-
-  /*
-   * Path to definition file
-   */
-  char *def_file;
-
-  /*
-   * First part of version number
-   */
-  uint16_t version_major;
-
-  /*
-   * Second part of version number
-   */
-  uint16_t version_minor;
-
-  /*
-   * Sensor description
-   */
-  char *description;
-
-  /*
-   * Sensor currently enabled
-   */
-  int enabled;
-
-  /*
-   * Category under which the sensor falls (e.g. tcp, datastore)
-   */
-  char *category;
-
-  /*
-   * When does the sensor become active
-   */
-  struct GNUNET_TIME_Absolute *start_time;
-
-  /*
-   * When does the sensor expire
-   */
-  struct GNUNET_TIME_Absolute *end_time;
-
-  /*
-   * Time interval to collect sensor information (e.g. every 1 min)
-   */
-  struct GNUNET_TIME_Relative interval;
-
-  /*
-   * Lifetime of an information sample after which it is deleted from storage
-   */
-  struct GNUNET_TIME_Relative lifetime;
-
-  /*
-   * A set of required peer capabilities for the sensor to collect meaningful information (e.g. ipv6)
-   */
-  char *capabilities;
-
-  /*
-   * Either "gnunet-statistics" or external "process"
-   */
-  char *source;
-
-  /*
-   * Name of the GNUnet service that is the source for the gnunet-statistics entry
-   */
-  char *gnunet_stat_service;
-
-  /*
-   * Name of the gnunet-statistics entry
-   */
-  char *gnunet_stat_name;
-
-  /**
-   * Handle to statistics get request (OR GNUNET_SCHEDULER_NO_TASK)
-   */
-  struct GNUNET_STATISTICS_GetHandle *gnunet_stat_get_handle;
-
-  /*
-   * Name of the external process to be executed
-   */
-  char *ext_process;
-
-  /*
-   * Arguments to be passed to the external process
-   */
-  char *ext_args;
-
-  /*
-   * The output datatype to be expected
-   */
-  char *expected_datatype;
-
-  /*
-   * Peer-identity of peer running collection point
-   */
-  struct GNUNET_PeerIdentity *collection_point;
-
-  /*
-   * Time interval to send sensor information to collection point (e.g. every 30 mins)
-   */
-  struct GNUNET_TIME_Relative *collection_interval;
-
-  /*
-   * Flag specifying if value is to be communicated to the p2p network
-   */
-  int p2p_report;
-
-  /*
-   * Time interval to communicate value to the p2p network
-   */
-  struct GNUNET_TIME_Relative *p2p_interval;
-
-  /*
-   * Execution task (OR GNUNET_SCHEDULER_NO_TASK)
-   */
-  GNUNET_SCHEDULER_TaskIdentifier execution_task;
-
-  /*
-   * Is the sensor being executed
-   */
-  int running;
-
-};
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
 
 /**
- * Our configuration.
+ * Path to sensor definitions directory
  */
-static const struct GNUNET_CONFIGURATION_Handle *cfg;
+static char *sensor_dir;
 
 /**
  * Hashmap of loaded sensor definitions
  */
-struct GNUNET_CONTAINER_MultiHashMap *sensors;
+static struct GNUNET_CONTAINER_MultiHashMap *sensors;
 
 /**
- * Supported sources of sensor information
+ * Handle to statistics service
  */
-static const char *sources[] = { "gnunet-statistics", "process", NULL };
+static struct GNUNET_STATISTICS_Handle *statistics;
 
 /**
- * Supported datatypes of sensor information
+ * Handle to peerstore service
  */
-static const char *datatypes[] = { "uint64", "double", "string", NULL };
+static struct GNUNET_PEERSTORE_Handle *peerstore;
 
 /**
- * Handle to statistics service
+ * Service name
  */
-struct GNUNET_STATISTICS_Handle *statistics;
-
-//TODO: logging macro that includes sensor info
+static char *subsystem = "sensor";
 
 /**
- * Remove sensor execution from scheduler
- *
- * @param cls unused
- * @param key hash of sensor name, key to hashmap
- * @param value a 'struct SensorInfo *'
- * @return #GNUNET_YES if we should continue to
- *         iterate,
- *         #GNUNET_NO if not.
+ * My peer id
  */
-int unschedule_sensor(void *cls,
-    const struct GNUNET_HashCode *key, void *value)
-{
-  struct SensorInfo *sensorinfo = value;
+static struct GNUNET_PeerIdentity peerid;
 
-  if(NULL != sensorinfo->gnunet_stat_get_handle)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Canceling a statistics get request for sensor `%s'\n", sensorinfo->name);
-    GNUNET_STATISTICS_get_cancel(sensorinfo->gnunet_stat_get_handle);
-  }
-  if(GNUNET_SCHEDULER_NO_TASK != sensorinfo->execution_task)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Unscheduling sensor `%s'\n", sensorinfo->name);
-    GNUNET_SCHEDULER_cancel(sensorinfo->execution_task);
-  }
-  return GNUNET_YES;
-}
 
 /**
- * Task run during shutdown.
- *
- * @param cls unused
- * @param tc unused
+ * Resets the service by stopping components, reloading sensors and starting
+ * components. This is needed when we receive new sensor updates.
  */
 static void
-shutdown_task (void *cls,
-              const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  GNUNET_CONTAINER_multihashmap_iterate(sensors, &unschedule_sensor, NULL);
-  if(NULL != statistics)
-    GNUNET_STATISTICS_destroy(statistics, GNUNET_YES);
-  GNUNET_SCHEDULER_shutdown();
-}
+reset ();
 
 
 /**
- * A client disconnected.  Remove all of its data structure entries.
+ * Change the state of the sensor.
+ * Write the change to file to make it persistent.
  *
- * @param cls closure, NULL
- * @param client identification of the client
+ * @param sensor sensor info struct
+ * @param state new enabled state: #GNUNET_YES / #GNUNET_NO
  */
 static void
-handle_client_disconnect (void *cls,
-                         struct GNUNET_SERVER_Client
-                         * client)
+set_sensor_enabled (struct GNUNET_SENSOR_SensorInfo *sensor, int state)
 {
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sensor `%s': Setting enabled to %d.\n",
+              sensor->name, state);
+  sensor->enabled = GNUNET_NO;
+  GNUNET_assert (NULL != sensor->cfg);
+  GNUNET_CONFIGURATION_set_value_string (sensor->cfg, sensor->name, "ENABLED",
+                                         (GNUNET_YES == state) ? "YES" : "NO");
+  GNUNET_CONFIGURATION_write (sensor->cfg, sensor->def_file);
 }
 
-/**
- * Parses a version number string into major and minor
- *
- * @param version full version string
- * @param major pointer to parsed major value
- * @param minor pointer to parsed minor value
- * @return #GNUNET_OK if parsing went ok, #GNUNET_SYSERROR in case of error
- */
-static int
-version_parse(char *version, uint16_t *major, uint16_t *minor)
-{
-  int majorval = 0;
-  int minorval = 0;
-
-  for(; isdigit(*version); version++)
-  {
-    majorval *= 10;
-    majorval += *version - '0';
-  }
-  if(*version != '.')
-    return GNUNET_SYSERR;
-  version++;
-  for(; isdigit(*version); version++)
-  {
-    minorval *= 10;
-    minorval += *version - '0';
-  }
-  if(*version != 0)
-    return GNUNET_SYSERR;
-  *major = majorval;
-  *minor = minorval;
-
-  return GNUNET_OK;
-}
 
 /**
- * Load sensor definition from configuration
- *
- * @param cfg configuration handle
- * @param sectionname configuration section containing definition
+ * Stops components and destroys sensors
  */
-static struct SensorInfo *
-load_sensor_from_cfg(struct GNUNET_CONFIGURATION_Handle *cfg, const char *sectionname)
-{
-  struct SensorInfo *sensor;
-  char *version_str;
-  char *starttime_str;
-  char *endtime_str;
-  unsigned long long time_sec;
-
-  sensor = GNUNET_new(struct SensorInfo);
-  //name
-  sensor->name = GNUNET_strdup(sectionname);
-  //version
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "VERSION", &version_str))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor version\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  if(GNUNET_OK != version_parse(version_str, &(sensor->version_major), &(sensor->version_minor)))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Invalid sensor version number, format should be major.minor\n"));
-    GNUNET_free(sensor);
-    GNUNET_free(version_str);
-    return NULL;
-  }
-  GNUNET_free(version_str);
-  //description
-  GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "DESCRIPTION", &sensor->description);
-  //category
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "CATEGORY", &sensor->category) ||
-        NULL == sensor->category)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor category\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  //enabled
-  if(GNUNET_NO == GNUNET_CONFIGURATION_get_value_yesno(cfg, sectionname, "ENABLED"))
-    sensor->enabled = GNUNET_NO;
-  else
-    sensor->enabled = GNUNET_YES;
-  //start time
-  sensor->start_time = NULL;
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "START_TIME", &starttime_str))
-  {
-    GNUNET_STRINGS_fancy_time_to_absolute(starttime_str, sensor->start_time);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Start time loaded: `%s'. Parsed: %d\n", starttime_str, (NULL != sensor->start_time));
-    GNUNET_free(starttime_str);
-  }
-  //end time
-  sensor->end_time = NULL;
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "END_TIME", &endtime_str))
-  {
-    GNUNET_STRINGS_fancy_time_to_absolute(endtime_str, sensor->end_time);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "End time loaded: `%s'. Parsed: %d\n", endtime_str, (NULL != sensor->end_time));
-    GNUNET_free(endtime_str);
-  }
-  //interval
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "INTERVAL", &time_sec))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor run interval\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  if(time_sec < MIN_INTERVAL)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Sensor run interval too low (%" PRIu64 " < %d)\n"),
-        time_sec, MIN_INTERVAL);
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  sensor->interval = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Interval loaded: %" PRIu64 "\n", sensor->interval.rel_value_us);
-  //lifetime
-  if(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, sectionname, "LIFETIME", &time_sec))
-  {
-    sensor->lifetime = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, time_sec);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Lifetime loaded: %" PRIu64 "\n", sensor->lifetime.rel_value_us);
-  }
-  else
-    sensor->lifetime = GNUNET_TIME_UNIT_FOREVER_REL;
-  //capabilities TODO
-  //source
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_choice(cfg, sectionname, "SOURCE", sources, &sensor->source))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor source\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  if(sources[0] == sensor->source) //gnunet-statistics
-  {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "GNUNET_STAT_SERVICE", &sensor->gnunet_stat_service) ||
-        GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "GNUNET_STAT_NAME", &sensor->gnunet_stat_name))
-    {
-      GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor gnunet-statistics source information\n"));
-      GNUNET_free(sensor);
-      return NULL;
-    }
-    sensor->gnunet_stat_get_handle = NULL;
-  }
-  else if(sources[1] == sensor->source) //process
-  {
-    if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "EXT_PROCESS", &sensor->ext_process))
-    {
-      GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor process name\n"));
-      GNUNET_free(sensor);
-      return NULL;
-    }
-    GNUNET_CONFIGURATION_get_value_string(cfg, sectionname, "EXT_ARGS", &sensor->ext_args);
-  }
-  //expected datatype
-  if(GNUNET_OK != GNUNET_CONFIGURATION_get_value_choice(cfg, sectionname, "EXPECTED_DATATYPE", datatypes, &sensor->expected_datatype))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error reading sensor expected datatype\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  if(sources[0] == sensor->source && datatypes[0] != sensor->expected_datatype)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Invalid expected datatype, gnunet-statistics returns uint64 values\n"));
-    GNUNET_free(sensor);
-    return NULL;
-  }
-  //TODO: reporting mechanism
-  //execution task
-  sensor->execution_task = GNUNET_SCHEDULER_NO_TASK;
-  //running
-  sensor->running = GNUNET_NO;
-
-  return sensor;
-}
-
-/**
- * Load sensor definition from file
- *
- * @param filename full path to file containing sensor definition
- */
-static struct SensorInfo *
-load_sensor_from_file(const char *filename)
+static void
+stop ()
 {
-  struct GNUNET_CONFIGURATION_Handle *sensorcfg;
-  const char *filebasename;
-  struct SensorInfo *sensor;
-
-  //test file
-  if(GNUNET_YES != GNUNET_DISK_file_test(filename))
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Failed to access sensor file: %s\n"), filename);
-    return NULL;
-  }
-  //load file as configuration
-  sensorcfg = GNUNET_CONFIGURATION_create();
-  if(GNUNET_SYSERR == GNUNET_CONFIGURATION_parse(sensorcfg, filename))
-  {
-    GNUNET_CONFIGURATION_destroy(sensorcfg);
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Failed to load sensor definition: %s\n"), filename);
-    return NULL;
-  }
-  //configuration section should be the same as filename
-  filebasename = GNUNET_STRINGS_get_short_name(filename);
-  sensor = load_sensor_from_cfg(sensorcfg, filebasename);
-  sensor->def_file = GNUNET_strdup(filename);
-
-  GNUNET_CONFIGURATION_destroy(sensorcfg);
-
-  return sensor;
+  SENSOR_update_stop ();
+  SENSOR_analysis_stop ();
+  SENSOR_reporting_value_stop ();
+  SENSOR_reporting_anomaly_stop ();
+  GNUNET_SENSOR_destroy_sensors (sensors);
 }
 
-/**
- * Compares version numbers of two sensors
- *
- * @param s1 first sensor
- * @param s2 second sensor
- * @return 1: s1 > s2, 0: s1 == s2, -1: s1 < s2
- */
-static int
-sensor_version_compare(struct SensorInfo *s1, struct SensorInfo *s2)
-{
-  if(s1->version_major == s2->version_major)
-    return (s1->version_minor < s2->version_minor) ? -1 : (s1->version_minor > s2->version_minor);
-  else
-    return (s1->version_major < s2->version_major) ? -1 : (s1->version_major > s2->version_major);
-}
 
 /**
- * Adds a new sensor to given hashmap.
- * If the same name exist, compares versions and update if old.
+ * Task run during shutdown.
  *
- * @param sensor Sensor structure to add
- * @param map Hashmap to add to
- * @return #GNUNET_YES if added, #GNUNET_NO if not added which is not necessarily an error
+ * @param cls unused
+ * @param tc unused
  */
-static int
-add_sensor_to_hashmap(struct SensorInfo *sensor, struct GNUNET_CONTAINER_MultiHashMap *map)
+static void
+shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  struct GNUNET_HashCode key;
-  struct SensorInfo *existing;
-
-  GNUNET_CRYPTO_hash(sensor->name, strlen(sensor->name), &key);
-  existing = GNUNET_CONTAINER_multihashmap_get(map, &key);
-  if(NULL != existing) //sensor with same name already exists
+  stop ();
+  if (NULL != statistics)
   {
-    if(sensor_version_compare(existing, sensor) >= 0) //same or newer version already exist
-    {
-      GNUNET_log(GNUNET_ERROR_TYPE_INFO, _("Sensor `%s' already exists with same or newer version\n"), sensor->name);
-      return GNUNET_NO;
-    }
-    else
-    {
-      GNUNET_CONTAINER_multihashmap_remove(map, &key, existing); //remove the old version
-      GNUNET_free(existing);
-      GNUNET_log(GNUNET_ERROR_TYPE_INFO, _("Upgrading sensor `%s' to a newer version\n"), sensor->name);
-    }
+    GNUNET_STATISTICS_destroy (statistics, GNUNET_YES);
+    statistics = NULL;
   }
-  if(GNUNET_SYSERR == GNUNET_CONTAINER_multihashmap_put(map, &key, sensor, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
+  if (NULL != peerstore)
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error adding new sensor `%s' to global hashmap, this should not happen\n"), sensor->name);
-    return GNUNET_NO;
+    GNUNET_PEERSTORE_disconnect (peerstore, GNUNET_YES);
+    peerstore = NULL;
   }
-
-  return GNUNET_YES;
-}
-
-/**
- * Iterating over files in sensors directory
- *
- * @param cls closure
- * @param filename complete filename (absolute path)
- * @return #GNUNET_OK to continue to iterate,
- *  #GNUNET_NO to stop iteration with no error,
- *  #GNUNET_SYSERR to abort iteration with error!
- */
-static int
-reload_sensors_dir_cb(void *cls, const char *filename)
-{
-  struct SensorInfo *sensor;
-
-  sensor = load_sensor_from_file(filename);
-  if(NULL == sensor)
+  if (NULL != sensor_dir)
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Error loading sensor from file: %s\n"), filename);
-    return GNUNET_OK;
+    GNUNET_free (sensor_dir);
+    sensor_dir = NULL;
   }
-  if(GNUNET_YES == add_sensor_to_hashmap(sensor, sensors))
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, _("Sensor `%s' added to global hashmap\n"), sensor->name);
-  else
-    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, ("Could not add sensor `%s' to global hashmap\n"), sensor->name);
-
-  return GNUNET_OK;
+  GNUNET_SCHEDULER_shutdown ();
 }
 
-/*
- * Get path to the directory containing the sensor definition files
- *
- * @return sensor files directory
- */
-static char *
-get_sensor_dir()
-{
-  char* datadir;
-  char* sensordir;
-
-  datadir = GNUNET_OS_installation_get_path(GNUNET_OS_IPK_DATADIR);
-  GNUNET_asprintf(&sensordir, "%ssensors%s",
-      datadir, DIR_SEPARATOR_STR);
-
-  return sensordir;
-}
 
 /**
- * Reads sensor definitions from data files
+ * A client disconnected.  Remove all of its data structure entries.
  *
+ * @param cls closure, NULL
+ * @param client identification of the client
  */
 static void
-reload_sensors()
+handle_client_disconnect (void *cls, struct GNUNET_SERVER_Client *client)
 {
-  char* sensordir;
-  int filesfound;
-
-  sensordir = get_sensor_dir();
-  GNUNET_log(GNUNET_ERROR_TYPE_INFO, _("Reloading sensor definitions from directory `%s'\n"), sensordir);
-  GNUNET_assert(GNUNET_YES == GNUNET_DISK_directory_test(sensordir, GNUNET_YES));
-
-  //read all files in sensors directory
-  filesfound = GNUNET_DISK_directory_scan(sensordir, &reload_sensors_dir_cb, NULL);
-  GNUNET_log(GNUNET_ERROR_TYPE_INFO, _("Loaded %d/%d sensors from directory `%s'\n"),
-      GNUNET_CONTAINER_multihashmap_size(sensors), filesfound, sensordir);
 }
 
+
 /**
- * Creates a structure with basic sensor info to be sent to a client
+ * Creates a structure with basic sensor info to be sent to a client.
  *
  * @param sensor sensor information
  * @return message ready to be sent to client
  */
 static struct SensorInfoMessage *
-create_sensor_info_msg(struct SensorInfo *sensor)
+create_sensor_info_msg (struct GNUNET_SENSOR_SensorInfo *sensor)
 {
   struct SensorInfoMessage *msg;
   uint16_t len;
@@ -597,34 +164,35 @@ create_sensor_info_msg(struct SensorInfo *sensor)
   size_t desc_len;
   char *str_ptr;
 
-  name_len = strlen(sensor->name);
-  if(NULL == sensor->description)
+  name_len = strlen (sensor->name);
+  if (NULL == sensor->description)
     desc_len = 0;
   else
-    desc_len = strlen(sensor->description);
+    desc_len = strlen (sensor->description) + 1;
   len = 0;
-  len += sizeof(struct SensorInfoMessage);
+  len += sizeof (struct SensorInfoMessage);
   len += name_len;
   len += desc_len;
-  msg = GNUNET_malloc(len);
-  msg->header.size = htons(len);
-  msg->header.type = htons(GNUNET_MESSAGE_TYPE_SENSOR_INFO);
-  msg->name_len = htons(name_len);
-  msg->description_len = htons(desc_len);
-  msg->version_major = htons(sensor->version_major);
-  msg->version_minor = htons(sensor->version_minor);
-  str_ptr = (char*) &msg[1];
-  memcpy(str_ptr, sensor->name, name_len);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Sending sensor name (%d): %.*s\n",
-        name_len, name_len, str_ptr);
+  msg = GNUNET_malloc (len);
+  msg->header.size = htons (len);
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_SENSOR_INFO);
+  msg->name_len = htons (name_len);
+  msg->description_len = htons (desc_len);
+  msg->version_major = htons (sensor->version_major);
+  msg->version_minor = htons (sensor->version_minor);
+  str_ptr = (char *) &msg[1];
+  memcpy (str_ptr, sensor->name, name_len);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending sensor name (%d): %.*s\n",
+              name_len, name_len, str_ptr);
   str_ptr += name_len;
-  memcpy(str_ptr, sensor->description, desc_len);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Sending sensor description (%d): %.*s\n",
-          desc_len, desc_len, str_ptr);
-
+  memcpy (str_ptr, sensor->description, desc_len);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Sending sensor description (%d): %.*s\n", desc_len, desc_len,
+              str_ptr);
   return msg;
 }
 
+
 /**
  * Handle GET SENSOR message.
  *
@@ -634,58 +202,69 @@ create_sensor_info_msg(struct SensorInfo *sensor)
  */
 static void
 handle_get_sensor (void *cls, struct GNUNET_SERVER_Client *client,
-            const struct GNUNET_MessageHeader *message)
+                   const struct GNUNET_MessageHeader *message)
 {
   struct GNUNET_SERVER_TransmitContext *tc;
   char *sensorname;
   size_t sensorname_len;
   struct GNUNET_HashCode key;
-  struct SensorInfo *sensorinfo;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo;
   struct SensorInfoMessage *msg;
 
-  sensorname = (char *)&message[1];
-  sensorname_len = ntohs(message->size) - sizeof(struct GNUNET_MessageHeader);
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO, "`%s' message received for sensor (%d) `%.*s'\n",
-              "GET SENSOR", sensorname_len, sensorname_len, sensorname);
+  sensorname = (char *) &message[1];
+  sensorname_len = ntohs (message->size) - sizeof (struct GNUNET_MessageHeader);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "`%s' message received for sensor (%d) `%.*s'\n", "GET SENSOR",
+              sensorname_len, sensorname_len, sensorname);
   tc = GNUNET_SERVER_transmit_context_create (client);
-  GNUNET_CRYPTO_hash(sensorname, sensorname_len, &key);
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Created key hash for requested sensor\n");
-  sensorinfo = (struct SensorInfo *)GNUNET_CONTAINER_multihashmap_get(sensors, &key);
-  if(NULL != sensorinfo)
-  {
-    msg = create_sensor_info_msg(sensorinfo);
-    GNUNET_SERVER_transmit_context_append_message(tc, (struct GNUNET_MessageHeader *)msg);
-    GNUNET_free(msg);
+  GNUNET_CRYPTO_hash (sensorname, sensorname_len, &key);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Created key hash for requested sensor\n");
+  sensorinfo =
+      (struct GNUNET_SENSOR_SensorInfo *)
+      GNUNET_CONTAINER_multihashmap_get (sensors, &key);
+  if (NULL != sensorinfo)
+  {
+    msg = create_sensor_info_msg (sensorinfo);
+    GNUNET_SERVER_transmit_context_append_message (tc,
+                                                   (struct GNUNET_MessageHeader
+                                                    *) msg);
+    GNUNET_free (msg);
   }
   else
-    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Requested sensor `%.*s' was not found\n",
-        sensorname_len, sensorname);
-  GNUNET_SERVER_transmit_context_append_data(tc, NULL, 0, GNUNET_MESSAGE_TYPE_SENSOR_END);
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Requested sensor `%.*s' was not found\n", sensorname_len,
+                sensorname);
+  GNUNET_SERVER_transmit_context_append_data (tc, NULL, 0,
+                                              GNUNET_MESSAGE_TYPE_SENSOR_END);
   GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL);
 }
 
+
 /**
  * Iterator for sensors and adds them to transmit context
  *
- * @param cls a 'struct GNUNET_SERVER_TransmitContext *'
+ * @param cls a `struct GNUNET_SERVER_TransmitContext *`
  * @param key hash of sensor name, key to hashmap
- * @param value a 'struct SensorInfo *'
+ * @param value a `struct GNUNET_SENSOR_SensorInfo *`
  */
-int add_sensor_to_tc(void *cls,
-    const struct GNUNET_HashCode *key, void *value)
+static int
+add_sensor_to_tc (void *cls, const struct GNUNET_HashCode *key, void *value)
 {
   struct GNUNET_SERVER_TransmitContext *tc = cls;
-  struct SensorInfo *sensorinfo = value;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = value;
   struct SensorInfoMessage *msg;
 
-  msg = create_sensor_info_msg(sensorinfo);
-  GNUNET_SERVER_transmit_context_append_message(tc, (struct GNUNET_MessageHeader *)msg);
-
-  GNUNET_free(msg);
+  msg = create_sensor_info_msg (sensorinfo);
+  GNUNET_SERVER_transmit_context_append_message (tc,
+                                                 (struct GNUNET_MessageHeader *)
+                                                 msg);
 
+  GNUNET_free (msg);
   return GNUNET_YES;
 }
 
+
 /**
  * Handle GET ALL SENSORS message.
  *
@@ -695,229 +274,360 @@ int add_sensor_to_tc(void *cls,
  */
 static void
 handle_get_all_sensors (void *cls, struct GNUNET_SERVER_Client *client,
-            const struct GNUNET_MessageHeader *message)
+                        const struct GNUNET_MessageHeader *message)
 {
   struct GNUNET_SERVER_TransmitContext *tc;
 
   GNUNET_log (GNUNET_ERROR_TYPE_INFO, "`%s' message received.\n",
-                "GET ALL SENSOR");
+              "GET ALL SENSOR");
   tc = GNUNET_SERVER_transmit_context_create (client);
-  GNUNET_CONTAINER_multihashmap_iterate(sensors, &add_sensor_to_tc, tc);
-  GNUNET_SERVER_transmit_context_append_data(tc, NULL, 0, GNUNET_MESSAGE_TYPE_SENSOR_END);
+  GNUNET_CONTAINER_multihashmap_iterate (sensors, &add_sensor_to_tc, tc);
+  GNUNET_SERVER_transmit_context_append_data (tc, NULL, 0,
+                                              GNUNET_MESSAGE_TYPE_SENSOR_END);
   GNUNET_SERVER_transmit_context_run (tc, GNUNET_TIME_UNIT_FOREVER_REL);
 }
 
+
 /**
  * Do a series of checks to determine if sensor should execute
  *
  * @return #GNUNET_YES / #GNUNET_NO
  */
 static int
-should_run_sensor(struct SensorInfo *sensorinfo)
+should_run_sensor (struct GNUNET_SENSOR_SensorInfo *sensorinfo)
 {
-  //FIXME: some checks should disable the sensor (e.g. expired)
   struct GNUNET_TIME_Absolute now;
 
-  if(GNUNET_NO == sensorinfo->enabled)
+  if (GNUNET_NO == sensorinfo->enabled)
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Sensor `%s' is disabled, will not run\n", sensorinfo->name);
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "Sensor `%s' is disabled, will not run\n", sensorinfo->name);
     return GNUNET_NO;
   }
-  now = GNUNET_TIME_absolute_get();
-  if(NULL != sensorinfo->start_time
-      && now.abs_value_us < sensorinfo->start_time->abs_value_us)
+  now = GNUNET_TIME_absolute_get ();
+  if (NULL != sensorinfo->start_time &&
+      now.abs_value_us < sensorinfo->start_time->abs_value_us)
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Start time for sensor `%s' not reached yet, will not run\n", sensorinfo->name);
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "Start time for sensor `%s' not reached yet, will not run\n",
+                sensorinfo->name);
     return GNUNET_NO;
   }
-  if(NULL != sensorinfo->end_time
-      && now.abs_value_us >= sensorinfo->end_time->abs_value_us)
+  if (NULL != sensorinfo->end_time &&
+      now.abs_value_us >= sensorinfo->end_time->abs_value_us)
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_INFO, "End time for sensor `%s' passed, will not run\n", sensorinfo->name);
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Sensor `%s' expired, disabling.\n",
+                sensorinfo->name);
+    set_sensor_enabled (sensorinfo, GNUNET_NO);
     return GNUNET_NO;
   }
   return GNUNET_YES;
 }
 
+
 /**
  * Callback function to process statistic values
  *
- * @param cls 'struct SensorInfo *'
- * @param subsystem name of subsystem that created the statistic
+ * @param cls `struct GNUNET_SENSOR_SensorInfo *`
+ * @param ss name of subsystem that created the statistic
  * @param name the name of the datum
  * @param value the current value
  * @param is_persistent #GNUNET_YES if the value is persistent, #GNUNET_NO if not
  * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
  */
-int sensor_statistics_iterator (void *cls,
-    const char *subsystem,
-    const char *name,
-    uint64_t value,
-    int is_persistent)
+static int
+sensor_statistics_iterator (void *cls, const char *ss, const char *name,
+                            uint64_t value, int is_persistent)
 {
-  struct SensorInfo *sensorinfo = cls;
-
-  GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Received a value for sensor `%s': %" PRIu64 "\n", sensorinfo->name, value);
-  return GNUNET_OK;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = cls;
+  double dvalue = (double) value;
+  struct GNUNET_TIME_Absolute expiry;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Received a value for sensor `%s': %" PRIu64 "\n",
+              sensorinfo->name, value);
+  expiry = GNUNET_TIME_relative_to_absolute (sensorinfo->lifetime);
+  GNUNET_PEERSTORE_store (peerstore, subsystem, &peerid, sensorinfo->name,
+                          &dvalue, sizeof (dvalue), expiry,
+                          GNUNET_PEERSTORE_STOREOPTION_MULTIPLE, NULL, NULL);
+  return GNUNET_SYSERR;         /* We only want one value */
 }
 
+
 /**
  * Continuation called after sensor gets all gnunet statistics values
  *
- * @param cls 'struct SensorInfo *'
+ * @param cls `struct GNUNET_SENSOR_SensorInfo *`
  * @param success #GNUNET_OK if statistics were
  *        successfully obtained, #GNUNET_SYSERR if not.
  */
-void end_sensor_run_stat (void *cls, int success)
+static void
+end_sensor_run_stat (void *cls, int success)
 {
-  struct SensorInfo *sensorinfo = cls;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = cls;
 
   sensorinfo->gnunet_stat_get_handle = NULL;
   sensorinfo->running = GNUNET_NO;
 }
 
+
+/**
+ * Tries to parse a received sensor value to its
+ * expected datatype
+ *
+ * @param value the string value received, should be null terminated
+ * @param sensor sensor information struct
+ * @param ret pointer to parsed value
+ * @return size of new parsed value, 0 for error
+ */
+static size_t
+parse_sensor_value (const char *value, struct GNUNET_SENSOR_SensorInfo *sensor,
+                    void **ret)
+{
+  double *dval;
+  char *endptr;
+
+  *ret = NULL;
+  if ('\0' == *value)
+    return 0;
+  if (0 == strcmp ("numeric", sensor->expected_datatype))
+  {
+    dval = GNUNET_new (double);
+
+    *dval = strtod (value, &endptr);
+    if (value == endptr)
+      return 0;
+    *ret = dval;
+    return sizeof (double);
+  }
+  if (0 == strcmp ("string", sensor->expected_datatype))
+  {
+    *ret = GNUNET_strdup (value);
+    return strlen (value) + 1;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+              _
+              ("Unknown value type expected by sensor, this should not happen.\n"));
+  return 0;
+}
+
+
 /**
  * Callback for output of executed sensor process
  *
- * @param cls 'struct SensorInfo *'
+ * @param cls `struct GNUNET_SENSOR_SensorInfo *`
  * @param line line of output from a command, NULL for the end
  */
-void sensor_process_callback (void *cls, const char *line)
+static void
+sensor_process_callback (void *cls, const char *line)
 {
-  struct SensorInfo *sensorinfo = cls;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = cls;
+  void *value;
+  size_t valsize;
+  struct GNUNET_TIME_Absolute expiry;
 
-  if(NULL == line)
+  if (NULL == line)
   {
+    GNUNET_OS_command_stop (sensorinfo->ext_cmd);
+    sensorinfo->ext_cmd = NULL;
     sensorinfo->running = GNUNET_NO;
+    sensorinfo->ext_cmd_value_received = GNUNET_NO;
     return;
   }
-  GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Received a value for sensor `%s': %s\n", sensorinfo->name, line);
+  if (GNUNET_YES == sensorinfo->ext_cmd_value_received)
+    return;                     /* We only want one *valid* value */
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Received a value for sensor `%s': %s\n",
+              sensorinfo->name, line);
+  valsize = parse_sensor_value (line, sensorinfo, &value);
+  if (valsize == 0)             /* invalid value, FIXME: should we disable the sensor now? */
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Received an invalid value for sensor `%s': %s\n"),
+                sensorinfo->name, line);
+  }
+  else
+  {
+    sensorinfo->ext_cmd_value_received = GNUNET_YES;
+    expiry = GNUNET_TIME_relative_to_absolute (sensorinfo->lifetime);
+    GNUNET_PEERSTORE_store (peerstore, subsystem, &peerid, sensorinfo->name,
+                            value, valsize, expiry,
+                            GNUNET_PEERSTORE_STOREOPTION_MULTIPLE, NULL, NULL);
+    GNUNET_free (value);
+  }
 }
 
+
+/**
+ * Checks if the given file is a path
+ *
+ * @return #GNUNET_YES / #GNUNET_NO
+ */
+static int
+is_path (char *filename)
+{
+  size_t filename_len;
+  int i;
+
+  filename_len = strlen (filename);
+  for (i = 0; i < filename_len; i++)
+  {
+    if (DIR_SEPARATOR == filename[i])
+      return GNUNET_YES;
+  }
+  return GNUNET_NO;
+}
+
+
 /**
  * Actual execution of a sensor
  *
  * @param cls 'struct SensorInfo'
  * @param tc unsed
  */
-void
-sensor_run (void *cls,
-    const struct GNUNET_SCHEDULER_TaskContext * tc)
+static void
+sensor_run (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  struct SensorInfo *sensorinfo = cls;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = cls;
   int check_result;
-  char *sensors_dir;
   char *process_path;
 
-  sensorinfo->execution_task = GNUNET_SCHEDULER_add_delayed(sensorinfo->interval, &sensor_run, sensorinfo);
-  if(GNUNET_YES == sensorinfo->running) //FIXME: should we try to kill?
+  sensorinfo->execution_task =
+      GNUNET_SCHEDULER_add_delayed (sensorinfo->interval, &sensor_run,
+                                    sensorinfo);
+  if (GNUNET_YES == sensorinfo->running)        //FIXME: should we try to kill?
   {
-    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Sensor `%s' running for too long, will try again next interval\n", sensorinfo->name);
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Sensor `%s' running for too long, will try again next interval\n",
+                sensorinfo->name);
     return;
   }
-  if(GNUNET_NO == should_run_sensor(sensorinfo))
+  if (GNUNET_NO == should_run_sensor (sensorinfo))
     return;
   sensorinfo->running = GNUNET_YES;
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Starting the execution of sensor `%s'\n", sensorinfo->name);
-  if(sources[0] == sensorinfo->source) //gnunet-statistics
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Starting the execution of sensor `%s'\n", sensorinfo->name);
+  if (0 == strcmp ("gnunet-statistics", sensorinfo->source))
   {
-    if(NULL == statistics)
-    {
-      statistics = GNUNET_STATISTICS_create("sensor", cfg);
-    }
-    sensorinfo->gnunet_stat_get_handle = GNUNET_STATISTICS_get(statistics,
-        sensorinfo->gnunet_stat_service,
-        sensorinfo->gnunet_stat_name,
-        sensorinfo->interval, //try to get values only for the interval of the sensor
-        &end_sensor_run_stat,
-        &sensor_statistics_iterator,
-        sensorinfo);
+    sensorinfo->gnunet_stat_get_handle = GNUNET_STATISTICS_get (statistics, sensorinfo->gnunet_stat_service, sensorinfo->gnunet_stat_name, sensorinfo->interval,        //try to get values only for the interval of the sensor
+                                                                &end_sensor_run_stat,
+                                                                &sensor_statistics_iterator,
+                                                                sensorinfo);
   }
-  else if(sources[1] == sensorinfo->source)
+  else if (0 == strcmp ("process", sensorinfo->source))
   {
-    //FIXME: break execution if process is a path
+    if (GNUNET_YES == is_path (sensorinfo->ext_process))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _
+                  ("Sensor `%s': External process should not be a path, disabling sensor.\n"),
+                  sensorinfo->name);
+      set_sensor_enabled (sensorinfo, GNUNET_NO);
+      return;
+    }
     //check if the process exists in $PATH
-    process_path = GNUNET_strdup(sensorinfo->ext_process);
+    process_path = GNUNET_strdup (sensorinfo->ext_process);
     check_result =
-        GNUNET_OS_check_helper_binary(sensorinfo->ext_process, GNUNET_NO, NULL); //search in $PATH
-    if(GNUNET_SYSERR == check_result)
+        GNUNET_OS_check_helper_binary (process_path, GNUNET_NO, NULL);
+    if (GNUNET_SYSERR == check_result)
     {
       //search in sensor directory
-      sensors_dir = get_sensor_dir();
-      GNUNET_free(process_path);
-      GNUNET_asprintf(&process_path, "%s%s-files%s%s",
-          sensors_dir,
-          sensorinfo->name,
-          DIR_SEPARATOR_STR,
-          sensorinfo->ext_process);
-      GNUNET_free(sensors_dir);
+      GNUNET_free (process_path);
+      GNUNET_asprintf (&process_path, "%s%s-files%s%s", sensor_dir,
+                       sensorinfo->name, DIR_SEPARATOR_STR,
+                       sensorinfo->ext_process);
+      GNUNET_free (sensor_dir);
       check_result =
-        GNUNET_OS_check_helper_binary(process_path, GNUNET_NO, NULL);
+          GNUNET_OS_check_helper_binary (process_path, GNUNET_NO, NULL);
     }
-    if(GNUNET_SYSERR == check_result)
+    if (GNUNET_SYSERR == check_result)
     {
-      GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Sensor `%s' process `%s' problem: binary doesn't exist or not executable\n",
-          sensorinfo->name,
-          sensorinfo->ext_process);
-      //FIXME: disable sensor here?
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _
+                  ("Sensor `%s' process `%s' problem: binary doesn't exist or not executable\n"),
+                  sensorinfo->name, sensorinfo->ext_process);
+      set_sensor_enabled (sensorinfo, GNUNET_NO);
       sensorinfo->running = GNUNET_NO;
-      GNUNET_free(process_path);
+      GNUNET_free (process_path);
       return;
     }
-    GNUNET_OS_command_run(&sensor_process_callback,
-        sensorinfo,
-        GNUNET_TIME_UNIT_FOREVER_REL,
-        process_path,
-        sensorinfo->ext_process,
-        sensorinfo->ext_args,
-        NULL);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Process started for sensor `%s'\n", sensorinfo->name);
+    sensorinfo->ext_cmd_value_received = GNUNET_NO;
+    sensorinfo->ext_cmd =
+        GNUNET_OS_command_run (&sensor_process_callback, sensorinfo,
+                               GNUNET_TIME_UNIT_FOREVER_REL, process_path,
+                               sensorinfo->ext_process, sensorinfo->ext_args,
+                               NULL);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Process started for sensor `%s'\n",
+                sensorinfo->name);
+    GNUNET_free (process_path);
   }
   else
   {
     sensorinfo->running = GNUNET_NO;
-    GNUNET_break(0); //shouldn't happen
+    GNUNET_break (0);           /* shouldn't happen */
   }
 }
 
+
 /**
  * Starts the execution of a sensor
  *
  * @param cls unused
  * @param key hash of sensor name, key to hashmap (unused)
- * @param value a 'struct SensorInfo *'
+ * @param value a `struct GNUNET_SENSOR_SensorInfo *`
  * @return #GNUNET_YES if we should continue to
  *         iterate,
  *         #GNUNET_NO if not.
  */
-int schedule_sensor(void *cls,
-    const struct GNUNET_HashCode *key, void *value)
+static int
+schedule_sensor (void *cls, const struct GNUNET_HashCode *key, void *value)
 {
-  struct SensorInfo *sensorinfo = value;
+  struct GNUNET_SENSOR_SensorInfo *sensorinfo = value;
 
-  if(GNUNET_NO == should_run_sensor(sensorinfo))
+  if (GNUNET_NO == should_run_sensor (sensorinfo))
     return GNUNET_YES;
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Scheduling sensor `%s' to run after %" PRIu64 " microseconds\n",
-      sensorinfo->name, sensorinfo->interval.rel_value_us);
-  if(GNUNET_SCHEDULER_NO_TASK != sensorinfo->execution_task)
-  {
-    GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Sensor `%s' execution task already set, this should not happen\n", sensorinfo->name);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Scheduling sensor `%s' to run after %" PRIu64 " microseconds\n",
+              sensorinfo->name, sensorinfo->interval.rel_value_us);
+  if (GNUNET_SCHEDULER_NO_TASK != sensorinfo->execution_task)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _
+                ("Sensor `%s' execution task already set, this should not happen\n"),
+                sensorinfo->name);
     return GNUNET_NO;
   }
-  sensorinfo->execution_task = GNUNET_SCHEDULER_add_delayed(sensorinfo->interval, &sensor_run, sensorinfo);
+  sensorinfo->execution_task =
+      GNUNET_SCHEDULER_add_delayed (sensorinfo->interval, &sensor_run,
+                                    sensorinfo);
   return GNUNET_YES;
 }
 
+
 /**
  * Starts the execution of all enabled sensors
- *
  */
 static void
-schedule_all_sensors()
+schedule_all_sensors ()
+{
+  GNUNET_CONTAINER_multihashmap_iterate (sensors, &schedule_sensor, NULL);
+}
+
+
+/**
+ * Loads sensors and starts different service components
+ */
+static void
+start ()
 {
-  GNUNET_CONTAINER_multihashmap_iterate(sensors, &schedule_sensor, NULL);
+  sensors = GNUNET_SENSOR_load_all_sensors (sensor_dir);
+  schedule_all_sensors ();
+  SENSOR_reporting_value_start (cfg, sensors);
+  SENSOR_reporting_anomaly_start (cfg, sensors);
+  SENSOR_analysis_start (cfg, sensors);
+  SENSOR_update_start (cfg, sensors, &reset);
 }
 
+
 /**
  * Process statistics requests.
  *
@@ -926,8 +636,7 @@ schedule_all_sensors()
  * @param c configuration to use
  */
 static void
-run (void *cls,
-     struct GNUNET_SERVER_Handle *server,
+run (void *cls, struct GNUNET_SERVER_Handle *server,
      const struct GNUNET_CONFIGURATION_Handle *c)
 {
   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
@@ -939,16 +648,30 @@ run (void *cls,
   };
 
   cfg = c;
-  sensors = GNUNET_CONTAINER_multihashmap_create(10, GNUNET_NO);
-  reload_sensors();
-  schedule_all_sensors();
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (cfg, "SENSOR", "SENSOR_DIR",
+                                               &sensor_dir))
+    sensor_dir = GNUNET_SENSOR_get_default_sensor_dir ();
+  statistics = GNUNET_STATISTICS_create ("sensor", cfg);
+  GNUNET_CRYPTO_get_peer_identity (cfg, &peerid);
+  peerstore = GNUNET_PEERSTORE_connect (cfg);
   GNUNET_SERVER_add_handlers (server, handlers);
-  GNUNET_SERVER_disconnect_notify (server, 
-                                  &handle_client_disconnect,
-                                  NULL);
-  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
-                               &shutdown_task,
-                               NULL);
+  GNUNET_SERVER_disconnect_notify (server, &handle_client_disconnect, NULL);
+  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
+                                NULL);
+  start ();
+}
+
+
+/**
+ * Resets the service by stopping components, reloading sensors and starting
+ * components. This is needed when we receive new sensor updates.
+ */
+static void
+reset ()
+{
+  stop ();
+  start ();
 }
 
 
@@ -963,11 +686,8 @@ int
 main (int argc, char *const *argv)
 {
   return (GNUNET_OK ==
-          GNUNET_SERVICE_run (argc,
-                              argv,
-                              "sensor",
-                             GNUNET_SERVICE_OPTION_NONE,
-                             &run, NULL)) ? 0 : 1;
+          GNUNET_SERVICE_run (argc, argv, "sensor", GNUNET_SERVICE_OPTION_NONE,
+                              &run, NULL)) ? 0 : 1;
 }
 
 /* end of gnunet-service-sensor.c */