/**
 * collectd - src/ipmi.c
 * Copyright (C) 2008-2009  Florian octo Forster
 * Copyright (C) 2008       Peter Holik
 * Copyright (C) 2009       Bruno Prémont
 *
 * This program 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; only version 2 of the License is applicable.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * Authors:
 *   Florian octo Forster <octo at collectd.org>
 *   Peter Holik <peter at holik.at>
 *   Bruno Prémont <bonbons at linux-vserver.org>
 *   Pavel Rochnyak <pavel2000 ngs.ru>
 **/

#include "collectd.h"

#include "plugin.h"
#include "utils/common/common.h"
#include "utils/ignorelist/ignorelist.h"

#include <OpenIPMI/ipmi_auth.h>
#include <OpenIPMI/ipmi_conn.h>
#include <OpenIPMI/ipmi_err.h>
#include <OpenIPMI/ipmi_lan.h>
#include <OpenIPMI/ipmi_posix.h>
#include <OpenIPMI/ipmi_smi.h>
#include <OpenIPMI/ipmiif.h>

#define ERR_BUF_SIZE 1024

/*
 * Private data types
 */
struct c_ipmi_sensor_list_s;
typedef struct c_ipmi_sensor_list_s c_ipmi_sensor_list_t;

struct c_ipmi_instance_s {
  char *name;
  ignorelist_t *ignorelist;
  ignorelist_t *sel_ignorelist;
  bool notify_add;
  bool notify_remove;
  bool notify_notpresent;
  bool notify_conn;
  bool sel_enabled;
  bool sel_clear_event;

  char *host;
  char *connaddr;
  char *username;
  char *password;
  unsigned int authtype;

  bool connected;
  ipmi_con_t *connection;
  pthread_mutex_t sensor_list_lock;
  c_ipmi_sensor_list_t *sensor_list;

  bool active;
  pthread_t thread_id;
  int init_in_progress;

  struct c_ipmi_instance_s *next;
};
typedef struct c_ipmi_instance_s c_ipmi_instance_t;

struct c_ipmi_sensor_list_s {
  ipmi_sensor_id_t sensor_id;
  char sensor_name[DATA_MAX_NAME_LEN];
  char sensor_type[DATA_MAX_NAME_LEN];
  char type_instance[DATA_MAX_NAME_LEN];
  int sensor_not_present;
  c_ipmi_sensor_list_t *next;
  c_ipmi_instance_t *instance;
  unsigned int use;
};

struct c_ipmi_db_type_map_s {
  enum ipmi_unit_type_e type;
  const char *type_name;
};
typedef struct c_ipmi_db_type_map_s c_ipmi_db_type_map_t;

/*
 * Module global variables
 */
static os_handler_t *os_handler;
static c_ipmi_instance_t *instances;

/*
 * Misc private functions
 */
static void c_ipmi_error(c_ipmi_instance_t *st, const char *func, int status) {
  char errbuf[ERR_BUF_SIZE] = {0};

  if (IPMI_IS_OS_ERR(status) || IPMI_IS_RMCPP_ERR(status) ||
      IPMI_IS_IPMI_ERR(status)) {
    ipmi_get_error_string(status, errbuf, sizeof(errbuf));
  }

  if (errbuf[0] == 0) {
    snprintf(errbuf, sizeof(errbuf), "Unknown error %#x", status);
  }
  errbuf[sizeof(errbuf) - 1] = '\0';

  ERROR("ipmi plugin: %s failed for `%s`: %s", func, st->name, errbuf);
} /* void c_ipmi_error */

static void c_ipmi_log(os_handler_t *handler, const char *format,
                       enum ipmi_log_type_e log_type, va_list ap) {
  char msg[ERR_BUF_SIZE];

  vsnprintf(msg, sizeof(msg), format, ap);

  switch (log_type) {
  case IPMI_LOG_INFO:
    INFO("ipmi plugin: %s", msg);
    break;
  case IPMI_LOG_WARNING:
    NOTICE("ipmi plugin: %s", msg);
    break;
  case IPMI_LOG_SEVERE:
    WARNING("ipmi plugin: %s", msg);
    break;
  case IPMI_LOG_FATAL:
    ERROR("ipmi plugin: %s", msg);
    break;
  case IPMI_LOG_ERR_INFO:
    ERROR("ipmi plugin: %s", msg);
    break;
#if COLLECT_DEBUG
  case IPMI_LOG_DEBUG_START:
  case IPMI_LOG_DEBUG:
    DEBUG("ipmi plugin: %s", msg);
    break;
  case IPMI_LOG_DEBUG_CONT:
  case IPMI_LOG_DEBUG_END:
    DEBUG("%s", msg);
    break;
#else
  case IPMI_LOG_DEBUG_START:
  case IPMI_LOG_DEBUG:
  case IPMI_LOG_DEBUG_CONT:
  case IPMI_LOG_DEBUG_END:
    break;
#endif
  }
} /* void c_ipmi_log */

static notification_t c_ipmi_notification_init(c_ipmi_instance_t const *st,
                                               int severity) {
  notification_t n = {severity, cdtime(), "", "", "ipmi", "", "", "", NULL};

  sstrncpy(n.host, (st->host != NULL) ? st->host : hostname_g, sizeof(n.host));
  return n;
} /* notification_t c_ipmi_notification_init */

/*
 * Sensor handlers
 */
/* Prototype for sensor_list_remove, so sensor_read_handler can call it. */
static int sensor_list_remove(c_ipmi_instance_t *st, ipmi_sensor_t *sensor);

static void sensor_read_handler(ipmi_sensor_t *sensor, int err,
                                enum ipmi_value_present_e value_present,
                                unsigned int __attribute__((unused)) raw_value,
                                double value, ipmi_states_t *states,
                                void *user_data) {
  value_list_t vl = VALUE_LIST_INIT;

  c_ipmi_sensor_list_t *list_item = user_data;
  c_ipmi_instance_t *st = list_item->instance;

  list_item->use--;

  if (err != 0) {
    if (IPMI_IS_IPMI_ERR(err) &&
        IPMI_GET_IPMI_ERR(err) == IPMI_NOT_PRESENT_CC) {
      if (list_item->sensor_not_present == 0) {
        list_item->sensor_not_present = 1;

        INFO("ipmi plugin: sensor_read_handler: sensor `%s` of `%s` "
             "not present.",
             list_item->sensor_name, st->name);

        if (st->notify_notpresent) {
          notification_t n = c_ipmi_notification_init(st, NOTIF_WARNING);

          sstrncpy(n.type_instance, list_item->type_instance,
                   sizeof(n.type_instance));
          sstrncpy(n.type, list_item->sensor_type, sizeof(n.type));
          snprintf(n.message, sizeof(n.message), "sensor %s not present",
                   list_item->sensor_name);

          plugin_dispatch_notification(&n);
        }
      }
    } else if (IPMI_IS_IPMI_ERR(err) &&
               IPMI_GET_IPMI_ERR(err) ==
                   IPMI_NOT_SUPPORTED_IN_PRESENT_STATE_CC) {
      INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` not ready.",
           list_item->sensor_name, st->name);
    } else if (IPMI_IS_IPMI_ERR(err) &&
               IPMI_GET_IPMI_ERR(err) == IPMI_TIMEOUT_CC) {
      INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` timed out.",
           list_item->sensor_name, st->name);
    } else {
      char errbuf[ERR_BUF_SIZE] = {0};
      ipmi_get_error_string(err, errbuf, sizeof(errbuf) - 1);

      if (IPMI_IS_IPMI_ERR(err))
        INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` failed: "
             "%s.",
             list_item->sensor_name, st->name, errbuf);
      else if (IPMI_IS_OS_ERR(err))
        INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` failed: "
             "%s (%#x).",
             list_item->sensor_name, st->name, errbuf, IPMI_GET_OS_ERR(err));
      else if (IPMI_IS_RMCPP_ERR(err))
        INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` failed: "
             "%s.",
             list_item->sensor_name, st->name, errbuf);
      else if (IPMI_IS_SOL_ERR(err))
        INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` failed: "
             "%s (%#x).",
             list_item->sensor_name, st->name, errbuf, IPMI_GET_SOL_ERR(err));
      else
        INFO("ipmi plugin: sensor_read_handler: Sensor `%s` of `%s` failed "
             "with error %#x. of class %#x",
             list_item->sensor_name, st->name, err & 0xff, err & 0xffffff00);
    }
    return;
  } else if (list_item->sensor_not_present == 1) {
    list_item->sensor_not_present = 0;

    INFO("ipmi plugin: sensor_read_handler: sensor `%s` of `%s` present.",
         list_item->sensor_name, st->name);

    if (st->notify_notpresent) {
      notification_t n = c_ipmi_notification_init(st, NOTIF_OKAY);

      sstrncpy(n.type_instance, list_item->type_instance,
               sizeof(n.type_instance));
      sstrncpy(n.type, list_item->sensor_type, sizeof(n.type));
      snprintf(n.message, sizeof(n.message), "sensor %s present",
               list_item->sensor_name);

      plugin_dispatch_notification(&n);
    }
  }

  if (value_present != IPMI_BOTH_VALUES_PRESENT) {
    INFO("ipmi plugin: sensor_read_handler: Removing sensor `%s` of `%s`, "
         "because it provides %s. If you need this sensor, "
         "please file a bug report.",
         list_item->sensor_name, st->name,
         (value_present == IPMI_RAW_VALUE_PRESENT) ? "only the raw value"
                                                   : "no value");
    sensor_list_remove(st, sensor);
    return;
  }

  if (!ipmi_is_sensor_scanning_enabled(states)) {
    DEBUG("ipmi plugin: sensor_read_handler: Skipping sensor `%s` of `%s`, "
          "it is in 'scanning disabled' state.",
          list_item->sensor_name, st->name);
    return;
  }

  if (ipmi_is_initial_update_in_progress(states)) {
    DEBUG("ipmi plugin: sensor_read_handler: Skipping sensor `%s` of `%s`, "
          "it is in 'initial update in progress' state.",
          list_item->sensor_name, st->name);
    return;
  }

  vl.values = &(value_t){.gauge = value};
  vl.values_len = 1;

  if (st->host != NULL)
    sstrncpy(vl.host, st->host, sizeof(vl.host));
  sstrncpy(vl.plugin, "ipmi", sizeof(vl.plugin));
  sstrncpy(vl.type, list_item->sensor_type, sizeof(vl.type));
  sstrncpy(vl.type_instance, list_item->type_instance,
           sizeof(vl.type_instance));

  plugin_dispatch_values(&vl);
} /* void sensor_read_handler */

static void sensor_get_name(ipmi_sensor_t *sensor, char *buffer, int buf_len) {
  char temp[DATA_MAX_NAME_LEN] = {0};
  ipmi_entity_t *ent = ipmi_sensor_get_entity(sensor);
  const char *entity_id_string = ipmi_entity_get_entity_id_string(ent);
  char sensor_name[DATA_MAX_NAME_LEN] = "";
  char *sensor_name_ptr;

  if ((buffer == NULL) || (buf_len == 0))
    return;

  ipmi_sensor_get_name(sensor, temp, sizeof(temp));
  temp[sizeof(temp) - 1] = '\0';

  if (entity_id_string != NULL && strlen(temp))
    snprintf(sensor_name, sizeof(sensor_name), "%s %s", temp, entity_id_string);
  else if (entity_id_string != NULL)
    sstrncpy(sensor_name, entity_id_string, sizeof(sensor_name));
  else
    sstrncpy(sensor_name, temp, sizeof(sensor_name));

  if (strlen(temp)) {
    sstrncpy(temp, sensor_name, sizeof(temp));
    sensor_name_ptr = strstr(temp, ").");
    if (sensor_name_ptr != NULL) {
      /* If name is something like "foo (123).bar",
       * change that to "bar (123)".
       * Both, sensor_name_ptr and sensor_id_ptr point to memory within the
       * `temp' array, which holds a copy of the current `sensor_name'. */
      char *sensor_id_ptr;

      /* `sensor_name_ptr' points to ").bar". */
      sensor_name_ptr[1] = 0;
      /* `temp' holds "foo (123)\0bar\0". */
      sensor_name_ptr += 2;
      /* `sensor_name_ptr' now points to "bar". */

      sensor_id_ptr = strstr(temp, "(");
      if (sensor_id_ptr != NULL) {
        /* `sensor_id_ptr' now points to "(123)". */
        snprintf(sensor_name, sizeof(sensor_name), "%s %s", sensor_name_ptr,
                 sensor_id_ptr);
      }
      /* else: don't touch sensor_name. */
    }
  }
  sstrncpy(buffer, sensor_name, buf_len);
}

static const char *sensor_unit_to_type(ipmi_sensor_t *sensor) {
  static const c_ipmi_db_type_map_t ipmi_db_type_map[] = {
      {IPMI_UNIT_TYPE_WATTS, "power"}, {IPMI_UNIT_TYPE_CFM, "flow"}};

  /* check the modifier and rate of the sensor value */
  if ((ipmi_sensor_get_modifier_unit_use(sensor) != IPMI_MODIFIER_UNIT_NONE) ||
      (ipmi_sensor_get_rate_unit(sensor) != IPMI_RATE_UNIT_NONE))
    return NULL;

  /* find the db type by using sensor base unit type */
  enum ipmi_unit_type_e ipmi_type = ipmi_sensor_get_base_unit(sensor);
  for (size_t i = 0; i < STATIC_ARRAY_SIZE(ipmi_db_type_map); i++)
    if (ipmi_db_type_map[i].type == ipmi_type)
      return ipmi_db_type_map[i].type_name;

  return NULL;
} /* const char* sensor_unit_to_type */

static int sensor_list_add(c_ipmi_instance_t *st, ipmi_sensor_t *sensor) {
  ipmi_sensor_id_t sensor_id;
  c_ipmi_sensor_list_t *list_item;
  c_ipmi_sensor_list_t *list_prev;

  char buffer[DATA_MAX_NAME_LEN] = {0};
  char *sensor_name_ptr = buffer;
  int sensor_type;
  const char *type;

  sensor_id = ipmi_sensor_convert_to_id(sensor);
  sensor_get_name(sensor, buffer, sizeof(buffer));

  DEBUG("ipmi plugin: sensor_list_add: Found sensor `%s` of `%s`,"
        " Type: %#x"
        " Event reading type: %#x"
        " Direction: %#x"
        " Event support: %#x",
        sensor_name_ptr, st->name, ipmi_sensor_get_sensor_type(sensor),
        ipmi_sensor_get_event_reading_type(sensor),
        ipmi_sensor_get_sensor_direction(sensor),
        ipmi_sensor_get_event_support(sensor));

  /* Both `ignorelist' and `sensor_name_ptr' may be NULL. */
  if (ignorelist_match(st->ignorelist, sensor_name_ptr) != 0)
    return 0;

  /* FIXME: Use rate unit or base unit to scale the value */

  sensor_type = ipmi_sensor_get_sensor_type(sensor);

  /*
   * ipmitool/lib/ipmi_sdr.c sdr_sensor_has_analog_reading() has a notice
   * about 'Threshold sensors' and 'analog readings'. Discrete sensor may
   * have analog data, but discrete sensors support is not implemented
   * in Collectd yet.
   *
   * ipmi_sensor_id_get_reading() supports only 'Threshold' sensors.
   * See lib/sensor.c:4842, stand_ipmi_sensor_get_reading() for details.
   */
  if (!ipmi_sensor_get_is_readable(sensor)) {
    INFO("ipmi plugin: sensor_list_add: Ignore sensor `%s` of `%s`, "
         "because it isn't readable! Its type: (%#x, %s). ",
         sensor_name_ptr, st->name, sensor_type,
         ipmi_sensor_get_sensor_type_string(sensor));
    return -1;
  }

  if (ipmi_sensor_get_event_reading_type(sensor) !=
      IPMI_EVENT_READING_TYPE_THRESHOLD) {
    INFO("ipmi plugin: sensor_list_add: Ignore sensor `%s` of `%s`, "
         "because it is discrete (%#x)! Its type: (%#x, %s). ",
         sensor_name_ptr, st->name, sensor_type,
         ipmi_sensor_get_event_reading_type(sensor),
         ipmi_sensor_get_sensor_type_string(sensor));
    return -1;
  }

  switch (sensor_type) {
  case IPMI_SENSOR_TYPE_TEMPERATURE:
    type = "temperature";
    break;

  case IPMI_SENSOR_TYPE_VOLTAGE:
    type = "voltage";
    break;

  case IPMI_SENSOR_TYPE_CURRENT:
    type = "current";
    break;

  case IPMI_SENSOR_TYPE_FAN:
    type = "fanspeed";
    break;

  case IPMI_SENSOR_TYPE_MEMORY:
    type = "memory";
    break;

  default: {
    /* try to get collectd DB type based on sensor base unit type */
    if ((type = sensor_unit_to_type(sensor)) != NULL)
      break;

    INFO("ipmi plugin: sensor_list_add: Ignore sensor `%s` of `%s`, "
         "because I don't know how to handle its units (%#x, %#x, %#x). "
         "Sensor type: (%#x, %s). If you need this sensor, please file "
         "a bug report at http://collectd.org/.",
         sensor_name_ptr, st->name, ipmi_sensor_get_base_unit(sensor),
         ipmi_sensor_get_modifier_unit(sensor),
         ipmi_sensor_get_rate_unit(sensor), sensor_type,
         ipmi_sensor_get_sensor_type_string(sensor));
    return -1;
  }
  } /* switch (sensor_type) */

  pthread_mutex_lock(&st->sensor_list_lock);

  list_prev = NULL;
  for (list_item = st->sensor_list; list_item != NULL;
       list_item = list_item->next) {
    if (ipmi_cmp_sensor_id(sensor_id, list_item->sensor_id) == 0)
      break;
    list_prev = list_item;
  } /* for (list_item) */

  if (list_item != NULL) {
    pthread_mutex_unlock(&st->sensor_list_lock);
    return 0;
  }

  list_item = calloc(1, sizeof(*list_item));
  if (list_item == NULL) {
    pthread_mutex_unlock(&st->sensor_list_lock);
    return -1;
  }

  list_item->instance = st;
  list_item->sensor_id = ipmi_sensor_convert_to_id(sensor);

  if (list_prev != NULL)
    list_prev->next = list_item;
  else
    st->sensor_list = list_item;

  /* if sensor provides the percentage value, use "percent" collectd type
     and add the `percent` to the type instance of the reported value */
  if (ipmi_sensor_get_percentage(sensor)) {
    snprintf(list_item->type_instance, sizeof(list_item->type_instance),
             "percent-%s", sensor_name_ptr);
    type = "percent";
  } else {
    /* use type instance as a name of the sensor */
    sstrncpy(list_item->type_instance, sensor_name_ptr,
             sizeof(list_item->type_instance));
  }

  sstrncpy(list_item->sensor_name, sensor_name_ptr,
           sizeof(list_item->sensor_name));
  sstrncpy(list_item->sensor_type, type, sizeof(list_item->sensor_type));

  pthread_mutex_unlock(&st->sensor_list_lock);

  if (st->notify_add && (st->init_in_progress == 0)) {
    notification_t n = c_ipmi_notification_init(st, NOTIF_OKAY);

    sstrncpy(n.type_instance, list_item->type_instance,
             sizeof(n.type_instance));
    sstrncpy(n.type, list_item->sensor_type, sizeof(n.type));
    snprintf(n.message, sizeof(n.message), "sensor %s added",
             list_item->sensor_name);

    plugin_dispatch_notification(&n);
  }

  return 0;
} /* int sensor_list_add */

static int sensor_list_remove(c_ipmi_instance_t *st, ipmi_sensor_t *sensor) {
  ipmi_sensor_id_t sensor_id;
  c_ipmi_sensor_list_t *list_item;
  c_ipmi_sensor_list_t *list_prev;

  sensor_id = ipmi_sensor_convert_to_id(sensor);

  pthread_mutex_lock(&st->sensor_list_lock);

  list_prev = NULL;
  for (list_item = st->sensor_list; list_item != NULL;
       list_item = list_item->next) {
    if (ipmi_cmp_sensor_id(sensor_id, list_item->sensor_id) == 0)
      break;
    list_prev = list_item;
  } /* for (list_item) */

  if (list_item == NULL) {
    pthread_mutex_unlock(&st->sensor_list_lock);
    return -1;
  }

  if (list_prev == NULL)
    st->sensor_list = list_item->next;
  else
    list_prev->next = list_item->next;

  list_prev = NULL;
  list_item->next = NULL;

  pthread_mutex_unlock(&st->sensor_list_lock);

  if (st->notify_remove && st->active) {
    notification_t n = c_ipmi_notification_init(st, NOTIF_WARNING);

    sstrncpy(n.type_instance, list_item->type_instance,
             sizeof(n.type_instance));
    sstrncpy(n.type, list_item->sensor_type, sizeof(n.type));
    snprintf(n.message, sizeof(n.message), "sensor %s removed",
             list_item->sensor_name);

    plugin_dispatch_notification(&n);
  }

  free(list_item);
  return 0;
} /* int sensor_list_remove */

static int sensor_list_read_all(c_ipmi_instance_t *st) {
  pthread_mutex_lock(&st->sensor_list_lock);

  for (c_ipmi_sensor_list_t *list_item = st->sensor_list; list_item != NULL;
       list_item = list_item->next) {
    DEBUG("ipmi plugin: try read sensor `%s` of `%s`, use: %d",
          list_item->sensor_name, st->name, list_item->use);

    /* Reading already initiated */
    if (list_item->use)
      continue;

    list_item->use++;
    ipmi_sensor_id_get_reading(list_item->sensor_id, sensor_read_handler,
                               /* user data = */ (void *)list_item);
  } /* for (list_item) */

  pthread_mutex_unlock(&st->sensor_list_lock);

  return 0;
} /* int sensor_list_read_all */

static int sensor_list_remove_all(c_ipmi_instance_t *st) {
  c_ipmi_sensor_list_t *list_item;

  pthread_mutex_lock(&st->sensor_list_lock);

  list_item = st->sensor_list;
  st->sensor_list = NULL;

  pthread_mutex_unlock(&st->sensor_list_lock);

  while (list_item != NULL) {
    c_ipmi_sensor_list_t *list_next = list_item->next;

    free(list_item);

    list_item = list_next;
  } /* while (list_item) */

  return 0;
} /* int sensor_list_remove_all */

static int sensor_convert_threshold_severity(enum ipmi_thresh_e severity) {
  switch (severity) {
  case IPMI_LOWER_NON_CRITICAL:
  case IPMI_UPPER_NON_CRITICAL:
    return NOTIF_OKAY;
  case IPMI_LOWER_CRITICAL:
  case IPMI_UPPER_CRITICAL:
    return NOTIF_WARNING;
  case IPMI_LOWER_NON_RECOVERABLE:
  case IPMI_UPPER_NON_RECOVERABLE:
    return NOTIF_FAILURE;
  default:
    return NOTIF_OKAY;
  } /* switch (severity) */
} /* int sensor_convert_threshold_severity */

static void add_event_common_data(notification_t *n, ipmi_sensor_t *sensor,
                                  enum ipmi_event_dir_e dir,
                                  ipmi_event_t *event) {
  ipmi_entity_t *ent = ipmi_sensor_get_entity(sensor);

  plugin_notification_meta_add_string(n, "entity_name",
                                      ipmi_entity_get_entity_id_string(ent));
  plugin_notification_meta_add_signed_int(n, "entity_id",
                                          ipmi_entity_get_entity_id(ent));
  plugin_notification_meta_add_signed_int(n, "entity_instance",
                                          ipmi_entity_get_entity_instance(ent));
  plugin_notification_meta_add_boolean(n, "assert", dir == IPMI_ASSERTION);

  if (event)
    plugin_notification_meta_add_signed_int(n, "event_type",
                                            ipmi_event_get_type(event));
} /* void add_event_sensor_meta_data */

static int sensor_threshold_event_handler(
    ipmi_sensor_t *sensor, enum ipmi_event_dir_e dir,
    enum ipmi_thresh_e threshold, enum ipmi_event_value_dir_e high_low,
    enum ipmi_value_present_e value_present, unsigned int raw_value,
    double value, void *cb_data, ipmi_event_t *event) {

  c_ipmi_instance_t *st = cb_data;

  /* From the IPMI specification Chapter 2: Events.
   * If a callback handles the event, then all future callbacks called due to
   * the event will receive a NULL for the event. So be ready to handle a NULL
   * event in all your event handlers. A NULL may also be passed to an event
   * handler if the callback was not due to an event. */
  if (event == NULL)
    return IPMI_EVENT_NOT_HANDLED;

  notification_t n = c_ipmi_notification_init(st, NOTIF_OKAY);
  /* offset is a table index and it's represented as enum of strings that are
     organized in the way - high and low for each threshold severity level */
  unsigned int offset = (2 * threshold) + high_low;
  unsigned int event_type = ipmi_sensor_get_event_reading_type(sensor);
  unsigned int sensor_type = ipmi_sensor_get_sensor_type(sensor);
  const char *event_state =
      ipmi_get_reading_name(event_type, sensor_type, offset);
  sensor_get_name(sensor, n.type_instance, sizeof(n.type_instance));
  if (value_present != IPMI_NO_VALUES_PRESENT)
    snprintf(n.message, sizeof(n.message),
             "sensor %s received event: %s, value is %f", n.type_instance,
             event_state, value);
  else
    snprintf(n.message, sizeof(n.message),
             "sensor %s received event: %s, value not provided",
             n.type_instance, event_state);

  DEBUG("Threshold event received for sensor %s", n.type_instance);

  sstrncpy(n.type, ipmi_sensor_get_sensor_type_string(sensor), sizeof(n.type));
  n.severity = sensor_convert_threshold_severity(threshold);
  n.time = NS_TO_CDTIME_T(ipmi_event_get_timestamp(event));

  plugin_notification_meta_add_string(&n, "severity",
                                      ipmi_get_threshold_string(threshold));
  plugin_notification_meta_add_string(&n, "direction",
                                      ipmi_get_value_dir_string(high_low));

  switch (value_present) {
  case IPMI_BOTH_VALUES_PRESENT:
    plugin_notification_meta_add_double(&n, "val", value);
  /* both values present, so fall-through to add raw value too */
  case IPMI_RAW_VALUE_PRESENT: {
    char buf[DATA_MAX_NAME_LEN] = {0};
    snprintf(buf, sizeof(buf), "0x%2.2x", raw_value);
    plugin_notification_meta_add_string(&n, "raw", buf);
  } break;
  default:
    break;
  } /* switch (value_present) */

  add_event_common_data(&n, sensor, dir, event);

  plugin_dispatch_notification(&n);
  plugin_notification_meta_free(n.meta);

  /* Delete handled ipmi event from the list */
  if (st->sel_clear_event) {
    ipmi_event_delete(event, NULL, NULL);
    return IPMI_EVENT_HANDLED;
  }

  return IPMI_EVENT_NOT_HANDLED;
} /* int sensor_threshold_event_handler */

static int sensor_discrete_event_handler(ipmi_sensor_t *sensor,
                                         enum ipmi_event_dir_e dir, int offset,
                                         int severity, int prev_severity,
                                         void *cb_data, ipmi_event_t *event) {

  c_ipmi_instance_t *st = cb_data;

  /* From the IPMI specification Chapter 2: Events.
   * If a callback handles the event, then all future callbacks called due to
   * the event will receive a NULL for the event. So be ready to handle a NULL
   * event in all your event handlers. A NULL may also be passed to an event
   * handler if the callback was not due to an event. */
  if (event == NULL)
    return IPMI_EVENT_NOT_HANDLED;

  notification_t n = c_ipmi_notification_init(st, NOTIF_OKAY);
  unsigned int event_type = ipmi_sensor_get_event_reading_type(sensor);
  unsigned int sensor_type = ipmi_sensor_get_sensor_type(sensor);
  const char *event_state =
      ipmi_get_reading_name(event_type, sensor_type, offset);
  sensor_get_name(sensor, n.type_instance, sizeof(n.type_instance));
  snprintf(n.message, sizeof(n.message), "sensor %s received event: %s",
           n.type_instance, event_state);

  DEBUG("Discrete event received for sensor %s", n.type_instance);

  sstrncpy(n.type, ipmi_sensor_get_sensor_type_string(sensor), sizeof(n.type));
  n.time = NS_TO_CDTIME_T(ipmi_event_get_timestamp(event));

  plugin_notification_meta_add_signed_int(&n, "offset", offset);

  if (severity != -1)
    plugin_notification_meta_add_signed_int(&n, "severity", severity);

  if (prev_severity != -1)
    plugin_notification_meta_add_signed_int(&n, "prevseverity", prev_severity);

  add_event_common_data(&n, sensor, dir, event);

  plugin_dispatch_notification(&n);
  plugin_notification_meta_free(n.meta);

  /* Delete handled ipmi event from the list */
  if (st->sel_clear_event) {
    ipmi_event_delete(event, NULL, NULL);
    return IPMI_EVENT_HANDLED;
  }

  return IPMI_EVENT_NOT_HANDLED;
} /* int sensor_discrete_event_handler */

static int sel_list_add(c_ipmi_instance_t *st, ipmi_sensor_t *sensor) {
  char sensor_name[DATA_MAX_NAME_LEN] = {0};
  int status = 0;

  /* Check if sensor on sel_ignorelist */
  sensor_get_name(sensor, sensor_name, sizeof(sensor_name));
  if (ignorelist_match(st->sel_ignorelist, sensor_name) != 0)
    return 0;

  /* register threshold event if threshold sensor support events */
  if (ipmi_sensor_get_event_reading_type(sensor) ==
      IPMI_EVENT_READING_TYPE_THRESHOLD)
    status = ipmi_sensor_add_threshold_event_handler(
        sensor, sensor_threshold_event_handler, st);
  /* register discrete handler if discrete/specific sensor support events */
  else if (ipmi_sensor_get_event_support(sensor) != IPMI_EVENT_SUPPORT_NONE)
    status = ipmi_sensor_add_discrete_event_handler(
        sensor, sensor_discrete_event_handler, st);

  if (status)
    ERROR("Unable to add sensor %s event handler, status: %d", sensor_name,
          status);
  return status;
}

static void sel_list_remove(c_ipmi_instance_t *st, ipmi_sensor_t *sensor) {
  if (ipmi_sensor_get_event_reading_type(sensor) ==
      IPMI_EVENT_READING_TYPE_THRESHOLD)
    ipmi_sensor_remove_threshold_event_handler(
        sensor, sensor_threshold_event_handler, st);
  else
    ipmi_sensor_remove_discrete_event_handler(
        sensor, sensor_discrete_event_handler, st);
}
/*
 * Entity handlers
 */
static void
entity_sensor_update_handler(enum ipmi_update_e op,
                             ipmi_entity_t __attribute__((unused)) * entity,
                             ipmi_sensor_t *sensor, void *user_data) {
  c_ipmi_instance_t *st = user_data;

  if ((op == IPMI_ADDED) || (op == IPMI_CHANGED)) {
    /* Will check for duplicate entries.. */
    sensor_list_add(st, sensor);
    if (st->sel_enabled)
      sel_list_add(st, sensor);
  } else if (op == IPMI_DELETED) {
    sensor_list_remove(st, sensor);
    if (st->sel_enabled)
      sel_list_remove(st, sensor);
  }
} /* void entity_sensor_update_handler */

/*
 * Domain handlers
 */
static void
domain_entity_update_handler(enum ipmi_update_e op,
                             ipmi_domain_t __attribute__((unused)) * domain,
                             ipmi_entity_t *entity, void *user_data) {
  int status;
  c_ipmi_instance_t *st = user_data;

  if (op == IPMI_ADDED) {
    status = ipmi_entity_add_sensor_update_handler(
        entity, entity_sensor_update_handler, /* user data = */ (void *)st);
    if (status != 0) {
      c_ipmi_error(st, "ipmi_entity_add_sensor_update_handler", status);
    }
  } else if (op == IPMI_DELETED) {
    status = ipmi_entity_remove_sensor_update_handler(
        entity, entity_sensor_update_handler, /* user data = */ (void *)st);
    if (status != 0) {
      c_ipmi_error(st, "ipmi_entity_remove_sensor_update_handler", status);
    }
  }
} /* void domain_entity_update_handler */

static void smi_event_handler(ipmi_con_t __attribute__((unused)) * ipmi,
                              const ipmi_addr_t __attribute__((unused)) * addr,
                              unsigned int __attribute__((unused)) addr_len,
                              ipmi_event_t *event, void *cb_data) {
  unsigned int type = ipmi_event_get_type(event);
  ipmi_domain_t *domain = cb_data;

  DEBUG("%s: Event received: type %u", __FUNCTION__, type);

  if (type != 0x02)
    /* It's not a standard IPMI event. */
    return;

  /* force domain to reread SELs */
  ipmi_domain_reread_sels(domain, NULL, NULL);
}

static void domain_connection_change_handler(ipmi_domain_t *domain, int err,
                                             unsigned int conn_num,
                                             unsigned int port_num,
                                             int still_connected,
                                             void *user_data) {

  DEBUG("domain_connection_change_handler (domain = %p, err = %i, "
        "conn_num = %u, port_num = %u, still_connected = %i, "
        "user_data = %p);",
        (void *)domain, err, conn_num, port_num, still_connected, user_data);

  c_ipmi_instance_t *st = user_data;

  if (err != 0)
    c_ipmi_error(st, "domain_connection_change_handler", err);

  if (!still_connected) {

    if (st->notify_conn && st->connected && st->init_in_progress == 0) {
      notification_t n = c_ipmi_notification_init(st, NOTIF_FAILURE);

      sstrncpy(n.message, "IPMI connection lost", sizeof(n.plugin));

      plugin_dispatch_notification(&n);
    }

    st->connected = false;
    return;
  }

  if (st->notify_conn && !st->connected && st->init_in_progress == 0) {
    notification_t n = c_ipmi_notification_init(st, NOTIF_OKAY);

    sstrncpy(n.message, "IPMI connection restored", sizeof(n.plugin));

    plugin_dispatch_notification(&n);
  }

  st->connected = true;

  int status = ipmi_domain_add_entity_update_handler(
      domain, domain_entity_update_handler, /* user data = */ st);
  if (status != 0) {
    c_ipmi_error(st, "ipmi_domain_add_entity_update_handler", status);
  }

  status = st->connection->add_event_handler(st->connection, smi_event_handler,
                                             (void *)domain);

  if (status != 0)
    c_ipmi_error(st, "Failed to register smi event handler", status);
} /* void domain_connection_change_handler */

static int c_ipmi_thread_init(c_ipmi_instance_t *st) {
  ipmi_domain_id_t domain_id;
  int status;

  if (st->connaddr != NULL) {
    status = ipmi_ip_setup_con(
        &st->connaddr, &(char *){IPMI_LAN_STD_PORT_STR}, 1, st->authtype,
        (unsigned int)IPMI_PRIVILEGE_USER, st->username, strlen(st->username),
        st->password, strlen(st->password), os_handler,
        /* user data = */ NULL, &st->connection);
    if (status != 0) {
      c_ipmi_error(st, "ipmi_ip_setup_con", status);
      return -1;
    }
  } else {
    status = ipmi_smi_setup_con(/* if_num = */ 0, os_handler,
                                /* user data = */ NULL, &st->connection);
    if (status != 0) {
      c_ipmi_error(st, "ipmi_smi_setup_con", status);
      return -1;
    }
  }

  ipmi_open_option_t opts[] = {
      {.option = IPMI_OPEN_OPTION_ALL, {.ival = 1}},
#ifdef IPMI_OPEN_OPTION_USE_CACHE
      /* OpenIPMI-2.0.17 and later: Disable SDR cache in local file */
      {.option = IPMI_OPEN_OPTION_USE_CACHE, {.ival = 0}},
#endif
  };

  /*
   * NOTE: Domain names must be unique. There is static `domains_list` common
   * to all threads inside lib/domain.c and some ops are done by name.
   */
  status = ipmi_open_domain(
      st->name, &st->connection, /* num_con = */ 1,
      domain_connection_change_handler, /* user data = */ (void *)st,
      /* domain_fully_up_handler = */ NULL, /* user data = */ NULL, opts,
      STATIC_ARRAY_SIZE(opts), &domain_id);
  if (status != 0) {
    c_ipmi_error(st, "ipmi_open_domain", status);
    return -1;
  }

  return 0;
} /* int c_ipmi_thread_init */

static void *c_ipmi_thread_main(void *user_data) {
  c_ipmi_instance_t *st = user_data;

  int status = c_ipmi_thread_init(st);
  if (status != 0) {
    ERROR("ipmi plugin: c_ipmi_thread_init failed.");
    st->active = false;
    return (void *)-1;
  }

  while (st->active) {
    struct timeval tv = {1, 0};
    os_handler->perform_one_op(os_handler, &tv);
  }
  return (void *)0;
} /* void *c_ipmi_thread_main */

static c_ipmi_instance_t *c_ipmi_init_instance() {
  c_ipmi_instance_t *st;

  st = calloc(1, sizeof(*st));
  if (st == NULL) {
    ERROR("ipmi plugin: calloc failed.");
    return NULL;
  }

  st->name = strdup("main");
  if (st->name == NULL) {
    sfree(st);
    ERROR("ipmi plugin: strdup() failed.");
    return NULL;
  }

  st->ignorelist = ignorelist_create(/* invert = */ 1);
  if (st->ignorelist == NULL) {
    sfree(st->name);
    sfree(st);
    ERROR("ipmi plugin: ignorelist_create() failed.");
    return NULL;
  }

  st->sel_ignorelist = ignorelist_create(/* invert = */ 1);
  if (st->sel_ignorelist == NULL) {
    ignorelist_free(st->ignorelist);
    sfree(st->name);
    sfree(st);
    ERROR("ipmi plugin: SEL ignorelist_create() failed.");
    return NULL;
  }

  st->sensor_list = NULL;
  pthread_mutex_init(&st->sensor_list_lock, /* attr = */ NULL);

  st->host = NULL;
  st->connaddr = NULL;
  st->username = NULL;
  st->password = NULL;
  st->authtype = IPMI_AUTHTYPE_DEFAULT;

  st->next = NULL;

  return st;
} /* c_ipmi_instance_t *c_ipmi_init_instance */

static void c_ipmi_free_instance(c_ipmi_instance_t *st) {
  if (st == NULL)
    return;

  assert(st->next == NULL);

  sfree(st->name);
  sfree(st->host);
  sfree(st->connaddr);
  sfree(st->username);
  sfree(st->password);

  ignorelist_free(st->sel_ignorelist);
  ignorelist_free(st->ignorelist);
  pthread_mutex_destroy(&st->sensor_list_lock);
  sfree(st);
} /* void c_ipmi_free_instance */

static void c_ipmi_add_instance(c_ipmi_instance_t *instance) {
  if (instances == NULL) {
    instances = instance;
    return;
  }

  c_ipmi_instance_t *last = instances;

  while (last->next != NULL)
    last = last->next;

  last->next = instance;
} /* void c_ipmi_add_instance */

static int c_ipmi_config_add_instance(oconfig_item_t *ci) {
  int status = 0;
  c_ipmi_instance_t *st = c_ipmi_init_instance();
  if (st == NULL)
    return ENOMEM;

  if (strcasecmp(ci->key, "Instance") == 0)
    status = cf_util_get_string(ci, &st->name);

  if (status != 0) {
    c_ipmi_free_instance(st);
    return status;
  }

  for (int i = 0; i < ci->children_num; i++) {
    oconfig_item_t *child = ci->children + i;

    if (strcasecmp("Sensor", child->key) == 0) {
      char *value = NULL;
      status = cf_util_get_string(child, &value);
      if (status != 0)
        break;
      ignorelist_add(st->ignorelist, value);
      sfree(value);
    } else if (strcasecmp("IgnoreSelected", child->key) == 0) {
      bool t;
      status = cf_util_get_boolean(child, &t);
      if (status != 0)
        break;
      ignorelist_set_invert(st->ignorelist, /* invert = */ !t);
    } else if (strcasecmp("NotifyIPMIConnectionState", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->notify_conn);
    } else if (strcasecmp("NotifySensorAdd", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->notify_add);
    } else if (strcasecmp("NotifySensorRemove", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->notify_remove);
    } else if (strcasecmp("NotifySensorNotPresent", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->notify_notpresent);
    } else if (strcasecmp("SELSensor", child->key) == 0) {
      char *value = NULL;
      status = cf_util_get_string(child, &value);
      if (status != 0)
        break;
      ignorelist_add(st->sel_ignorelist, value);
      sfree(value);
    } else if (strcasecmp("SELIgnoreSelected", child->key) == 0) {
      bool t;
      status = cf_util_get_boolean(child, &t);
      if (status != 0)
        break;
      ignorelist_set_invert(st->sel_ignorelist, /* invert = */ !t);
    } else if (strcasecmp("SELEnabled", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->sel_enabled);
    } else if (strcasecmp("SELClearEvent", child->key) == 0) {
      status = cf_util_get_boolean(child, &st->sel_clear_event);
    } else if (strcasecmp("Host", child->key) == 0)
      status = cf_util_get_string(child, &st->host);
    else if (strcasecmp("Address", child->key) == 0)
      status = cf_util_get_string(child, &st->connaddr);
    else if (strcasecmp("Username", child->key) == 0)
      status = cf_util_get_string(child, &st->username);
    else if (strcasecmp("Password", child->key) == 0)
      status = cf_util_get_string(child, &st->password);
    else if (strcasecmp("AuthType", child->key) == 0) {
      char tmp[8];
      status = cf_util_get_string_buffer(child, tmp, sizeof(tmp));
      if (status != 0)
        break;

      if (strcasecmp("MD5", tmp) == 0)
        st->authtype = IPMI_AUTHTYPE_MD5;
      else if (strcasecmp("rmcp+", tmp) == 0)
        st->authtype = IPMI_AUTHTYPE_RMCP_PLUS;
      else
        WARNING("ipmi plugin: The value \"%s\" is not valid for the "
                "\"AuthType\" option.",
                tmp);
    } else {
      WARNING("ipmi plugin: Option `%s' not allowed here.", child->key);
      status = -1;
    }

    if (status != 0)
      break;
  }

  if (status != 0) {
    c_ipmi_free_instance(st);
    return status;
  }

  c_ipmi_add_instance(st);

  return 0;
} /* int c_ipmi_config_add_instance */

static int c_ipmi_config(oconfig_item_t *ci) {
  bool have_instance_block = 0;

  for (int i = 0; i < ci->children_num; i++) {
    oconfig_item_t *child = ci->children + i;

    if (strcasecmp("Instance", child->key) == 0) {
      int status = c_ipmi_config_add_instance(child);
      if (status != 0)
        return status;

      have_instance_block = 1;
    } else if (!have_instance_block) {
      /* Non-instance option: Assume legacy configuration (without <Instance />
       * blocks) and call c_ipmi_config_add_instance with the <Plugin /> block.
       */
      WARNING("ipmi plugin: Legacy configuration found! Please update your "
              "config file.");
      return c_ipmi_config_add_instance(ci);
    } else {
      WARNING("ipmi plugin: The configuration option "
              "\"%s\" is not allowed here. Did you "
              "forget to add an <Instance /> block "
              "around the configuration?",
              child->key);
      return -1;
    }
  } /* for (ci->children) */

  return 0;
} /* int c_ipmi_config */

static int c_ipmi_read(user_data_t *user_data) {
  c_ipmi_instance_t *st = user_data->data;

  if (st->active == false) {
    INFO("ipmi plugin: c_ipmi_read: I'm not active, returning false.");
    return -1;
  }

  if (st->connected == false)
    return 0;

  sensor_list_read_all(st);

  if (st->init_in_progress > 0)
    st->init_in_progress--;
  else
    st->init_in_progress = 0;

  return 0;
} /* int c_ipmi_read */

static int c_ipmi_init(void) {
  c_ipmi_instance_t *st;
  char callback_name[3 * DATA_MAX_NAME_LEN];

  if (os_handler != NULL) {
    return 0;
  }

  os_handler = ipmi_posix_thread_setup_os_handler(SIGIO);
  if (os_handler == NULL) {
    ERROR("ipmi plugin: ipmi_posix_thread_setup_os_handler failed.");
    return -1;
  }

  os_handler->set_log_handler(os_handler, c_ipmi_log);

  if (ipmi_init(os_handler) != 0) {
    ERROR("ipmi plugin: ipmi_init() failed.");
    os_handler->free_os_handler(os_handler);
    return -1;
  };

  if (instances == NULL) {
    /* No instances were configured, let's start a default instance. */
    st = c_ipmi_init_instance();
    if (st == NULL)
      return ENOMEM;

    c_ipmi_add_instance(st);
  }

  /* Don't send `ADD' notifications during startup (~ 1 minute) */
  int cycles = 1 + (int)(TIME_T_TO_CDTIME_T(60) / plugin_get_interval());

  st = instances;
  while (NULL != st) {
    /* The `st->name` is used as "domain name" for ipmi_open_domain().
     * That value should be unique, so we do plugin_register_complex_read()
     * at first as it checks the uniqueness. */
    snprintf(callback_name, sizeof(callback_name), "ipmi/%s", st->name);

    user_data_t ud = {
        .data = st,
    };

    int status = plugin_register_complex_read(
        /* group     = */ "ipmi",
        /* name      = */ callback_name,
        /* callback  = */ c_ipmi_read,
        /* interval  = */ 0,
        /* user_data = */ &ud);

    if (status != 0) {
      st = st->next;
      continue;
    }

    st->init_in_progress = cycles;
    st->active = true;

    status = plugin_thread_create(&st->thread_id, /* attr = */ NULL,
                                  c_ipmi_thread_main,
                                  /* user data = */ (void *)st, "ipmi");

    if (status != 0) {
      st->active = false;
      st->thread_id = (pthread_t){0};

      plugin_unregister_read(callback_name);

      ERROR("ipmi plugin: pthread_create failed for `%s`.", callback_name);
    }

    st = st->next;
  }

  return 0;
} /* int c_ipmi_init */

static int c_ipmi_shutdown(void) {
  c_ipmi_instance_t *st = instances;
  instances = NULL;

  while (st != NULL) {
    c_ipmi_instance_t *next = st->next;

    st->next = NULL;
    st->active = false;

    if (!pthread_equal(st->thread_id, (pthread_t){0})) {
      pthread_join(st->thread_id, NULL);
      st->thread_id = (pthread_t){0};
    }

    sensor_list_remove_all(st);
    c_ipmi_free_instance(st);

    st = next;
  }

  os_handler->free_os_handler(os_handler);
  os_handler = NULL;

  return 0;
} /* int c_ipmi_shutdown */

void module_register(void) {
  plugin_register_complex_config("ipmi", c_ipmi_config);
  plugin_register_init("ipmi", c_ipmi_init);
  plugin_register_shutdown("ipmi", c_ipmi_shutdown);
} /* void module_register */
