snmp plugin: Added the first prototype of an SNMP plugin.

Querying simple values already works.

diff --git a/configure.in b/configure.in
index e44074982b5bb7f3af4007fd8429cb85732b1dc8..f259bf6cce32debf556bf8971c0e1142dad821d2 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1349,6 +1349,7 @@ AC_COLLECTD([ping],      [disable], [module], [ping statistics])
 AC_COLLECTD([processes], [disable], [module], [processes statistics])
 AC_COLLECTD([sensors],   [disable], [module], [lm_sensors statistics])
 AC_COLLECTD([serial],    [disable], [module], [serial statistics])
+AC_COLLECTD([snmp],      [disable], [module], [serial statistics])
 AC_COLLECTD([logfile],   [disable], [module], [logfile log facility])
 AC_COLLECTD([swap],      [disable], [module], [swap statistics])
 AC_COLLECTD([syslog],    [disable], [module], [syslog log facility])
@@ -1423,6 +1424,7 @@ Configuration:
     processes . . . . . $enable_processes
     sensors . . . . . . $enable_sensors
     serial  . . . . . . $enable_serial
+    snmp  . . . . . . . $enable_snmp
     swap  . . . . . . . $enable_swap
     syslog  . . . . . . $enable_syslog
     tape  . . . . . . . $enable_tape

diff --git a/src/Makefile.am b/src/Makefile.am
index 6fd656220ad8b87f326c88587876a63882764a2a..a1f2afa50e9bea705ccb7143b43001bca5fe71f3 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -471,6 +471,14 @@ collectd_LDADD += "-dlopen" serial.la
 collectd_DEPENDENCIES += serial.la
 endif
 
+if BUILD_MODULE_SNMP
+pkglib_LTLIBRARIES += snmp.la
+snmp_la_SOURCES = snmp.c
+snmp_la_LDFLAGS = -module -avoid-version -lsnmp
+collectd_LDADD += "-dlopen" snmp.la
+collectd_DEPENDENCIES += snmp.la
+endif
+
 if BUILD_MODULE_SWAP
 pkglib_LTLIBRARIES += swap.la
 swap_la_SOURCES = swap.c

diff --git a/src/snmp.c b/src/snmp.c
new file mode 100644 (file)
index 0000000..972bc29
--- /dev/null
+++ b/src/snmp.c
@@ -0,0 +1,768 @@
+/**
+ * collectd - src/snmp.c
+ * Copyright (C) 2007  Florian octo Forster
+ *
+ * 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 verplant.org>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+
+/*
+ * Private data structes
+ */
+struct oid_s
+{
+  oid oid[MAX_OID_LEN];
+  uint32_t oid_len;
+};
+typedef struct oid_s oid_t;
+
+union instance_u
+{
+  char  string[DATA_MAX_NAME_LEN];
+  oid_t oid;
+};
+typedef union instance_u instance_t;
+
+struct data_definition_s
+{
+  char *name; /* used to reference this from the `Collect' option */
+  char *type; /* used to find the data_set */
+  int is_table;
+  instance_t instance;
+  oid_t *values;
+  int values_len;
+  struct data_definition_s *next;
+};
+typedef struct data_definition_s data_definition_t;
+
+struct host_definition_s
+{
+  char *name;
+  char *address;
+  char *community;
+  int version;
+  struct snmp_session sess;
+  data_definition_t **data_list;
+  int data_list_len;
+  struct host_definition_s *next;
+};
+typedef struct host_definition_s host_definition_t;
+
+/*
+ * Private variables
+ */
+data_definition_t *data_head = NULL;
+host_definition_t *host_head = NULL;
+
+/*
+ * Private functions
+ */
+/* First there are many functions which do configuration stuff. It's a big
+ * bloated and messy, I'm afraid. */
+
+/*
+ * Callgraph for the config stuff:
+ *  csnmp_config
+ *  +-> csnmp_config_add_data
+ *  !   +-> csnmp_config_add_data_type
+ *  !   +-> csnmp_config_add_data_table
+ *  !   +-> csnmp_config_add_data_instance
+ *  !   +-> csnmp_config_add_data_values
+ *  +-> csnmp_config_add_host
+ *  +-> csnmp_config_add_collect
+ */
+static void call_snmp_init_once (void)
+{
+  static int have_init = 0;
+
+  if (have_init == 0)
+    init_snmp (PACKAGE_NAME);
+  have_init = 1;
+} /* void call_snmp_init_once */
+
+static int csnmp_config_add_data_type (data_definition_t *dd, oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: `Type' needs exactly one string argument.");
+    return (-1);
+  }
+
+  if (dd->type != NULL)
+    free (dd->type);
+
+  dd->type = strdup (ci->values[0].value.string);
+  if (dd->type == NULL)
+    return (-1);
+
+  return (0);
+} /* int csnmp_config_add_data_type */
+
+static int csnmp_config_add_data_table (data_definition_t *dd, oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_BOOLEAN))
+  {
+    WARNING ("snmp plugin: `Table' needs exactly one boolean argument.");
+    return (-1);
+  }
+
+  dd->is_table = ci->values[0].value.boolean ? 1 : 0;
+
+  return (0);
+} /* int csnmp_config_add_data_table */
+
+static int csnmp_config_add_data_instance (data_definition_t *dd, oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: `Instance' needs exactly one string argument.");
+    return (-1);
+  }
+
+  if (dd->is_table)
+  {
+    /* Instance is an OID */
+    dd->instance.oid.oid_len = MAX_OID_LEN;
+
+    if (!read_objid (ci->values[0].value.string,
+         dd->instance.oid.oid, &dd->instance.oid.oid_len))
+    {
+      ERROR ("snmp plugin: read_objid (%s) failed.",
+         ci->values[0].value.string);
+      return (-1);
+    }
+  }
+  else
+  {
+    /* Instance is a simple string */
+    strncpy (dd->instance.string, ci->values[0].value.string, DATA_MAX_NAME_LEN - 1);
+  }
+
+  return (0);
+} /* int csnmp_config_add_data_instance */
+
+static int csnmp_config_add_data_values (data_definition_t *dd, oconfig_item_t *ci)
+{
+  int i;
+
+  if (ci->values_num < 1)
+  {
+    WARNING ("snmp plugin: `Values' needs at least one argument.");
+    return (-1);
+  }
+
+  for (i = 0; i < ci->values_num; i++)
+    if (ci->values[i].type != OCONFIG_TYPE_STRING)
+    {
+      WARNING ("snmp plugin: `Values' needs only string argument.");
+      return (-1);
+    }
+
+  if (dd->values != NULL)
+    free (dd->values);
+  dd->values = (oid_t *) malloc (sizeof (oid_t) * ci->values_num);
+  if (dd->values == NULL)
+    return (-1);
+  dd->values_len = ci->values_num;
+
+  for (i = 0; i < ci->values_num; i++)
+  {
+    dd->values[i].oid_len = MAX_OID_LEN;
+
+    if (NULL == snmp_parse_oid (ci->values[i].value.string,
+         dd->values[i].oid, &dd->values[i].oid_len))
+    {
+      ERROR ("snmp plugin: snmp_parse_oid (%s) failed.",
+         ci->values[i].value.string);
+      free (dd->values);
+      dd->values = NULL;
+      dd->values_len = 0;
+      return (-1);
+    }
+  }
+
+  return (0);
+} /* int csnmp_config_add_data_instance */
+
+static int csnmp_config_add_data (oconfig_item_t *ci)
+{
+  data_definition_t *dd;
+  int status = 0;
+  int i;
+
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: The `Data' config option needs exactly one string argument.");
+    return (-1);
+  }
+
+  dd = (data_definition_t *) malloc (sizeof (data_definition_t));
+  if (dd == NULL)
+    return (-1);
+  memset (dd, '\0', sizeof (data_definition_t));
+
+  dd->name = strdup (ci->values[0].value.string);
+  if (dd->name == NULL)
+  {
+    free (dd);
+    return (-1);
+  }
+
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *option = ci->children + i;
+    status = 0;
+
+    if (strcasecmp ("Type", option->key) == 0)
+      status = csnmp_config_add_data_type (dd, option);
+    else if (strcasecmp ("Table", option->key) == 0)
+      status = csnmp_config_add_data_table (dd, option);
+    else if (strcasecmp ("Instance", option->key) == 0)
+      status = csnmp_config_add_data_instance (dd, option);
+    else if (strcasecmp ("Values", option->key) == 0)
+      status = csnmp_config_add_data_values (dd, option);
+    else
+    {
+      WARNING ("snmp plugin: Option `%s' not allowed here.", option->key);
+      status = -1;
+    }
+
+    if (status != 0)
+      break;
+  } /* for (ci->children) */
+
+  while (status == 0)
+  {
+    if (dd->type == NULL)
+    {
+      WARNING ("snmp plugin: `Type' not given for data `%s'", dd->name);
+      status = -1;
+      break;
+    }
+    if (dd->values == NULL)
+    {
+      WARNING ("snmp plugin: No `Value' given for data `%s'", dd->name);
+      status = -1;
+      break;
+    }
+
+    break;
+  } /* while (status == 0) */
+
+  if (status != 0)
+  {
+    sfree (dd->name);
+    sfree (dd->values);
+    sfree (dd);
+    return (-1);
+  }
+
+  DEBUG ("snmp plugin: dd = { name = %s, type = %s, is_table = %s, values_len = %i }",
+      dd->name, dd->type, (dd->is_table != 0) ? "true" : "false", dd->values_len);
+
+  if (data_head == NULL)
+    data_head = dd;
+  else
+  {
+    data_definition_t *last;
+    last = data_head;
+    while (last->next != NULL)
+      last = last->next;
+    last->next = dd;
+  }
+
+  return (0);
+} /* int csnmp_config_add_data */
+
+static int csnmp_config_add_host_address (host_definition_t *hd, oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: The `Address' config option needs exactly one string argument.");
+    return (-1);
+  }
+
+  if (hd->address == NULL)
+    free (hd->address);
+
+  hd->address = strdup (ci->values[0].value.string);
+  if (hd->address == NULL)
+    return (-1);
+
+  DEBUG ("snmp plugin: host = %s; host->address = %s;",
+      hd->name, hd->address);
+
+  hd->sess.peername = hd->address;
+
+  return (0);
+} /* int csnmp_config_add_host_address */
+
+static int csnmp_config_add_host_community (host_definition_t *hd, oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: The `Community' config option needs exactly one string argument.");
+    return (-1);
+  }
+
+  if (hd->community == NULL)
+    free (hd->community);
+
+  hd->community = strdup (ci->values[0].value.string);
+  if (hd->community == NULL)
+    return (-1);
+
+  DEBUG ("snmp plugin: host = %s; host->community = %s;",
+      hd->name, hd->community);
+
+  hd->sess.community = (u_char *) hd->community;
+  hd->sess.community_len = strlen (hd->community);
+
+  return (0);
+} /* int csnmp_config_add_host_community */
+
+static int csnmp_config_add_host_version (host_definition_t *hd, oconfig_item_t *ci)
+{
+  int version;
+
+  if ((ci->values_num != 1)
+      || (ci->values[0].type != OCONFIG_TYPE_NUMBER))
+  {
+    WARNING ("snmp plugin: The `Version' config option needs exactly one number argument.");
+    return (-1);
+  }
+
+  version = (int) ci->values[0].value.number;
+  if ((version != 1) && (version != 2))
+  {
+    WARNING ("snmp plugin: `Version' must either be `1' or `2'.");
+    return (-1);
+  }
+
+  hd->version = version;
+
+  if (hd->version == 1)
+    hd->sess.version = SNMP_VERSION_1;
+  else
+    hd->sess.version = SNMP_VERSION_2c;
+
+  return (0);
+} /* int csnmp_config_add_host_address */
+
+static int csnmp_config_add_host (oconfig_item_t *ci)
+{
+  host_definition_t *hd;
+  int status = 0;
+  int i;
+
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: `Host' needs exactly one string argument.");
+    return (-1);
+  }
+
+  hd = (host_definition_t *) malloc (sizeof (host_definition_t));
+  if (hd == NULL)
+    return (-1);
+  memset (hd, '\0', sizeof (host_definition_t));
+  hd->version = 2;
+
+  hd->name = strdup (ci->values[0].value.string);
+  if (hd->name == NULL)
+  {
+    free (hd);
+    return (-1);
+  }
+
+  snmp_sess_init (&hd->sess);
+  hd->sess.version = SNMP_VERSION_2c;
+
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *option = ci->children + i;
+    status = 0;
+
+    if (strcasecmp ("Address", option->key) == 0)
+      status = csnmp_config_add_host_address (hd, option);
+    else if (strcasecmp ("Community", option->key) == 0)
+      status = csnmp_config_add_host_community (hd, option);
+    else if (strcasecmp ("Version", option->key) == 0)
+      status = csnmp_config_add_host_version (hd, option);
+    else
+    {
+      WARNING ("snmp plugin: csnmp_config_add_host: Option `%s' not allowed here.", option->key);
+      status = -1;
+    }
+
+    if (status != 0)
+      break;
+  } /* for (ci->children) */
+
+  while (status == 0)
+  {
+    if (hd->address == NULL)
+    {
+      WARNING ("snmp plugin: `Address' not given for host `%s'", hd->name);
+      status = -1;
+      break;
+    }
+    if (hd->community == NULL)
+    {
+      WARNING ("snmp plugin: `Community' not given for host `%s'", hd->name);
+      status = -1;
+      break;
+    }
+
+    break;
+  } /* while (status == 0) */
+
+  if (status != 0)
+  {
+    sfree (hd->name);
+    sfree (hd);
+    return (-1);
+  }
+
+  /* TODO: Check all fields in `hd'. */
+  DEBUG ("snmp plugin: hd = { name = %s, address = %s, community = %s, version = %i }",
+      hd->name, hd->address, hd->community, hd->version);
+
+  if (host_head == NULL)
+    host_head = hd;
+  else
+  {
+    host_definition_t *last;
+    last = host_head;
+    while (last->next != NULL)
+      last = last->next;
+    last->next = hd;
+  }
+
+  return (0);
+} /* int csnmp_config_add_host */
+
+static int csnmp_config_add_collect (oconfig_item_t *ci)
+{
+  data_definition_t *data;
+  host_definition_t *host;
+  data_definition_t **data_list;
+  int data_list_len;
+  int i;
+
+  if (ci->values_num < 2)
+  {
+    WARNING ("snmp plugin: `Collect' needs at least two arguments.");
+    return (-1);
+  }
+
+  for (i = 0; i < ci->values_num; i++)
+    if (ci->values[i].type != OCONFIG_TYPE_STRING)
+    {
+      WARNING ("snmp plugin: All arguments to `Collect' must be strings.");
+      return (-1);
+    }
+
+  for (host = host_head; host != NULL; host = host->next)
+    if (strcasecmp (ci->values[0].value.string, host->name) == 0)
+      break;
+
+  if (host == NULL)
+  {
+    WARNING ("snmp plugin: No such host configured: `%s'",
+       ci->values[0].value.string);
+    return (-1);
+  }
+
+  data_list_len = host->data_list_len + ci->values_num - 1;
+  data_list = (data_definition_t **) realloc (host->data_list,
+      sizeof (data_definition_t *) * data_list_len);
+  if (data_list == NULL)
+    return (-1);
+  host->data_list = data_list;
+
+  for (i = 1; i < ci->values_num; i++)
+  {
+    for (data = data_head; data != NULL; data = data->next)
+      if (strcasecmp (ci->values[i].value.string, data->name) == 0)
+       break;
+
+    if (data == NULL)
+    {
+      WARNING ("snmp plugin: No such data configured: `%s'",
+         ci->values[i].value.string);
+      continue;
+    }
+
+    DEBUG ("snmp plugin: Collect: host = %s, data[%i] = %s;",
+       host->name, host->data_list_len, data->name);
+
+    host->data_list[host->data_list_len] = data;
+    host->data_list_len++;
+  } /* for (values_num) */
+
+  return (0);
+} /* int csnmp_config_add_collect */
+
+static int csnmp_config (oconfig_item_t *ci)
+{
+  int i;
+
+  call_snmp_init_once ();
+
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *child = ci->children + i;
+    if (strcasecmp ("Data", child->key) == 0)
+      csnmp_config_add_data (child);
+    else if (strcasecmp ("Host", child->key) == 0)
+      csnmp_config_add_host (child);
+    else if (strcasecmp ("Collect", child->key) == 0)
+      csnmp_config_add_collect (child);
+    else
+    {
+      WARNING ("snmp plugin: Ignoring unknown config option `%s'.", child->key);
+    }
+  } /* for (ci->children) */
+
+  return (0);
+} /* int csnmp_config */
+
+static int csnmp_init (void)
+{
+  call_snmp_init_once ();
+  return (0);
+}
+
+#if 0
+static void csnmp_submit (gauge_t snum, gauge_t mnum, gauge_t lnum)
+{
+  value_t values[3];
+  value_list_t vl = VALUE_LIST_INIT;
+
+  values[0].gauge = snum;
+  values[1].gauge = mnum;
+  values[2].gauge = lnum;
+
+  vl.values = values;
+  vl.values_len = STATIC_ARRAY_SIZE (values);
+  vl.time = time (NULL);
+  strcpy (vl.host, hostname_g);
+  strcpy (vl.plugin, "load");
+
+  plugin_dispatch_values ("load", &vl);
+}
+#endif
+
+static value_t csnmp_value_list_to_value (struct variable_list *vl, int type)
+{
+  value_t ret;
+  uint64_t temp = 0;
+  int defined = 1;
+
+  if ((vl->type == ASN_INTEGER)
+      || (vl->type == ASN_UINTEGER)
+      || (vl->type == ASN_COUNTER)
+      || (vl->type == ASN_GAUGE))
+  {
+    temp = *vl->val.integer;
+  }
+  else if (vl->type == ASN_COUNTER64)
+  {
+    temp = vl->val.counter64->high;
+    temp = temp << 32;
+    temp += vl->val.counter64->low;
+  }
+  else
+  {
+    WARNING ("snmp plugin: I don't know the ASN type `%i'", (int) vl->type);
+    defined = 0;
+  }
+
+  if (type == DS_TYPE_COUNTER)
+  {
+    ret.counter = temp;
+  }
+  else if (type == DS_TYPE_GAUGE)
+  {
+    ret.gauge = NAN;
+    if (defined != 0)
+      ret.gauge = temp;
+  }
+
+  return (ret);
+} /* value_t csnmp_value_list_to_value */
+
+static int csnmp_read_table (struct snmp_session *sess_ptr,
+    host_definition_t *host, data_definition_t *data)
+{
+  return (0);
+} /* int csnmp_read_table */
+
+static int csnmp_read_value (struct snmp_session *sess_ptr,
+    host_definition_t *host, data_definition_t *data)
+{
+  struct snmp_pdu *req;
+  struct snmp_pdu *res;
+  struct variable_list *vb;
+
+  const data_set_t *ds;
+  value_list_t vl = VALUE_LIST_INIT;
+
+  int status;
+  int i;
+
+  DEBUG ("snmp plugin: csnmp_read_value (host = %s, data = %s)",
+      host->name, data->name);
+
+  ds = plugin_get_ds (data->type);
+  if (!ds)
+  {
+    ERROR ("snmp plugin: DataSet `%s' not defined.", data->type);
+    return (-1);
+  }
+
+  if (ds->ds_num != data->values_len)
+  {
+    ERROR ("snmp plugin: DataSet `%s' requires %i values, but config talks about %i",
+       data->type, ds->ds_num, data->values_len);
+    return (-1);
+  }
+
+  vl.values_len = ds->ds_num;
+  vl.values = (value_t *) malloc (sizeof (value_t) * vl.values_len);
+  if (vl.values == NULL)
+    return (-1);
+  for (i = 0; i < vl.values_len; i++)
+  {
+    if (ds->ds[i].type == DS_TYPE_COUNTER)
+      vl.values[i].counter = 0;
+    else
+      vl.values[i].gauge = NAN;
+  }
+
+  strncpy (vl.host, host->name, sizeof (vl.host));
+  vl.host[sizeof (vl.host) - 1] = '\0';
+  strcpy (vl.plugin, "snmp");
+  strncpy (vl.type_instance, data->instance.string, sizeof (vl.type_instance));
+  vl.type_instance[sizeof (vl.type_instance) - 1] = '\0';
+
+  req = snmp_pdu_create (SNMP_MSG_GET);
+  if (req == NULL)
+  {
+    ERROR ("snmp plugin: snmp_pdu_create failed.");
+    sfree (vl.values);
+    return (-1);
+  }
+
+  for (i = 0; i < data->values_len; i++)
+    snmp_add_null_var (req, data->values[i].oid, data->values[i].oid_len);
+  status = snmp_synch_response (sess_ptr, req, &res);
+
+  if (status != STAT_SUCCESS)
+  {
+    ERROR ("snmp plugin: snmp_synch_response failed.");
+    sfree (vl.values);
+    return (-1);
+  }
+
+  vl.time = time (NULL);
+
+  for (vb = res->variables; vb != NULL; vb = vb->next_variable)
+  {
+    char buffer[1024];
+    snprint_variable (buffer, sizeof (buffer),
+       vb->name, vb->name_length, vb);
+    DEBUG ("snmp plugin: Got this variable: %s", buffer);
+
+    for (i = 0; i < data->values_len; i++)
+      if (snmp_oid_compare (data->values[i].oid, data->values[i].oid_len,
+           vb->name, vb->name_length) == 0)
+       vl.values[i] = csnmp_value_list_to_value (vb, ds->ds[i].type);
+  } /* for (res->variables) */
+
+  snmp_free_pdu (res);
+
+  DEBUG ("snmp plugin: -> plugin_dispatch_values (%s, &vl);", data->type);
+  plugin_dispatch_values (data->type, &vl);
+
+  return (0);
+} /* int csnmp_read_value */
+
+static int csnmp_read_host (host_definition_t *host)
+{
+  struct snmp_session *sess_ptr;
+  int i;
+
+  DEBUG ("snmp plugin: csnmp_read_host (%s);", host->name);
+
+  sess_ptr = snmp_open (&host->sess);
+  if (sess_ptr == NULL)
+  {
+    snmp_perror ("snmp_open");
+    ERROR ("snmp plugin: snmp_open failed.");
+    return (-1);
+  }
+
+  for (i = 0; i < host->data_list_len; i++)
+  {
+    data_definition_t *data = host->data_list[i];
+
+    if (data->is_table)
+      csnmp_read_table (sess_ptr, host, data);
+    else
+      csnmp_read_value (sess_ptr, host, data);
+  }
+
+  snmp_close (sess_ptr);
+  return (0);
+} /* int csnmp_read_host */
+
+static int csnmp_read (void)
+{
+  host_definition_t *host;
+
+  if (host_head == NULL)
+  {
+    INFO ("snmp plugin: No hosts configured.");
+    return (-1);
+  }
+
+  for (host = host_head; host != NULL; host = host->next)
+    csnmp_read_host (host);
+
+  return (0);
+} /* int csnmp_read */
+
+void module_register (void)
+{
+  plugin_register_complex_config ("snmp", csnmp_config);
+  plugin_register_init ("snmp", csnmp_init);
+  plugin_register_read ("snmp", csnmp_read);
+} /* void module_register */
+
+/*
+ * vim: shiftwidth=2 softtabstop=2 tabstop=8
+ */