X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fsnmp.c;h=00df3779bb52907c001de892b5ffae6ce9c5a442;hb=4212d170f8eb1a72608fc8f5f5c34837badc64ba;hp=622d64885e989ef49c719c5e819e71b50a4a09f5;hpb=1b59d618ba9c6849796ff313cee742082ad08eb1;p=collectd.git

diff --git a/src/snmp.c b/src/snmp.c
index 622d6488..00df3779 100644
--- a/src/snmp.c
+++ b/src/snmp.c
@@ -22,6 +22,7 @@
 #include "collectd.h"
 #include "common.h"
 #include "plugin.h"
+#include "utils_complain.h"
 
 #include <pthread.h>
 
@@ -51,6 +52,7 @@ struct data_definition_s
   char *type; /* used to find the data_set */
   int is_table;
   instance_t instance;
+  char *instance_prefix;
   oid_t *values;
   int values_len;
   double scale;
@@ -66,17 +68,10 @@ struct host_definition_s
   char *community;
   int version;
   void *sess_handle;
-  int16_t skip_num;
-  int16_t skip_left;
+  c_complain_t complaint;
+  uint32_t interval;
   data_definition_t **data_list;
   int data_list_len;
-  enum          /****************************************************/
-  {             /* This host..                                      */
-    STATE_IDLE, /* - just sits there until `skip_left < interval_g' */
-    STATE_WAIT, /* - waits to be queried.                           */
-    STATE_BUSY  /* - is currently being queried.                    */
-  } state;      /****************************************************/
-  struct host_definition_s *next;
 };
 typedef struct host_definition_s host_definition_t;
 
@@ -101,20 +96,51 @@ typedef struct csnmp_table_values_s csnmp_table_values_t;
 /*
  * Private variables
  */
-static int do_shutdown = 0;
-
-pthread_t *threads = NULL;
-int threads_num = 0;
-
 static data_definition_t *data_head = NULL;
-static host_definition_t *host_head = NULL;
 
-static pthread_mutex_t host_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t  host_cond = PTHREAD_COND_INITIALIZER;
+/*
+ * Prototypes
+ */
+static int csnmp_read_host (user_data_t *ud);
 
 /*
  * Private functions
  */
+static void csnmp_host_close_session (host_definition_t *host) /* {{{ */
+{
+  if (host->sess_handle == NULL)
+    return;
+
+  snmp_sess_close (host->sess_handle);
+  host->sess_handle = NULL;
+} /* }}} void csnmp_host_close_session */
+
+static void csnmp_host_definition_destroy (void *arg) /* {{{ */
+{
+  host_definition_t *hd;
+
+  hd = arg;
+
+  if (hd == NULL)
+    return;
+
+  if (hd->name != NULL)
+  {
+    DEBUG ("snmp plugin: Destroying host definition for host `%s'.",
+	hd->name);
+  }
+
+  csnmp_host_close_session (hd);
+
+  sfree (hd->name);
+  sfree (hd->address);
+  sfree (hd->community);
+  sfree (hd->data_list);
+
+  sfree (hd);
+} /* }}} void csnmp_host_definition_destroy */
+
+/* Many functions to handle the configuration. {{{ */
 /* First there are many functions which do configuration stuff. It's a big
  * bloated and messy, I'm afraid. */
 
@@ -126,6 +152,7 @@ static pthread_cond_t  host_cond = PTHREAD_COND_INITIALIZER;
  *  !   +-> csnmp_config_add_data_type
  *  !   +-> csnmp_config_add_data_table
  *  !   +-> csnmp_config_add_data_instance
+ *  !   +-> csnmp_config_add_data_instance_prefix
  *  !   +-> csnmp_config_add_data_values
  *  +-> csnmp_config_add_host
  *      +-> csnmp_config_add_host_address
@@ -151,9 +178,7 @@ static int csnmp_config_add_data_type (data_definition_t *dd, oconfig_item_t *ci
     return (-1);
   }
 
-  if (dd->type != NULL)
-    free (dd->type);
-
+  sfree (dd->type);
   dd->type = strdup (ci->values[0].value.string);
   if (dd->type == NULL)
     return (-1);
@@ -198,12 +223,37 @@ static int csnmp_config_add_data_instance (data_definition_t *dd, oconfig_item_t
   else
   {
     /* Instance is a simple string */
-    strncpy (dd->instance.string, ci->values[0].value.string, DATA_MAX_NAME_LEN - 1);
+    sstrncpy (dd->instance.string, ci->values[0].value.string,
+	sizeof (dd->instance.string));
   }
 
   return (0);
 } /* int csnmp_config_add_data_instance */
 
+static int csnmp_config_add_data_instance_prefix (data_definition_t *dd,
+    oconfig_item_t *ci)
+{
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
+  {
+    WARNING ("snmp plugin: `InstancePrefix' needs exactly one string argument.");
+    return (-1);
+  }
+
+  if (!dd->is_table)
+  {
+    WARNING ("snmp plugin: data %s: InstancePrefix is ignored when `Table' "
+	"is set to `false'.", dd->name);
+    return (-1);
+  }
+
+  sfree (dd->instance_prefix);
+  dd->instance_prefix = strdup (ci->values[0].value.string);
+  if (dd->instance_prefix == NULL)
+    return (-1);
+
+  return (0);
+} /* int csnmp_config_add_data_instance_prefix */
+
 static int csnmp_config_add_data_values (data_definition_t *dd, oconfig_item_t *ci)
 {
   int i;
@@ -221,8 +271,8 @@ static int csnmp_config_add_data_values (data_definition_t *dd, oconfig_item_t *
       return (-1);
     }
 
-  if (dd->values != NULL)
-    free (dd->values);
+  sfree (dd->values);
+  dd->values_len = 0;
   dd->values = (oid_t *) malloc (sizeof (oid_t) * ci->values_num);
   if (dd->values == NULL)
     return (-1);
@@ -313,6 +363,8 @@ static int csnmp_config_add_data (oconfig_item_t *ci)
       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 ("InstancePrefix", option->key) == 0)
+      status = csnmp_config_add_data_instance_prefix (dd, option);
     else if (strcasecmp ("Values", option->key) == 0)
       status = csnmp_config_add_data_values (dd, option);
     else if (strcasecmp ("Shift", option->key) == 0)
@@ -350,6 +402,7 @@ static int csnmp_config_add_data (oconfig_item_t *ci)
   if (status != 0)
   {
     sfree (dd->name);
+    sfree (dd->instance_prefix);
     sfree (dd->values);
     sfree (dd);
     return (-1);
@@ -492,8 +545,6 @@ static int csnmp_config_add_host_collect (host_definition_t *host,
 
 static int csnmp_config_add_host_interval (host_definition_t *hd, oconfig_item_t *ci)
 {
-  int interval;
-
   if ((ci->values_num != 1)
       || (ci->values[0].type != OCONFIG_TYPE_NUMBER))
   {
@@ -501,10 +552,9 @@ static int csnmp_config_add_host_interval (host_definition_t *hd, oconfig_item_t
     return (-1);
   }
 
-  interval = (int) ci->values[0].value.number;
-  hd->skip_num = interval;
-  if (hd->skip_num < 0)
-    hd->skip_num = 0;
+  hd->interval = ci->values[0].value.number >= 0
+    ? (uint32_t) ci->values[0].value.number
+    : 0;
 
   return (0);
 } /* int csnmp_config_add_host_interval */
@@ -515,6 +565,11 @@ static int csnmp_config_add_host (oconfig_item_t *ci)
   int status = 0;
   int i;
 
+  /* Registration stuff. */
+  char cb_name[DATA_MAX_NAME_LEN];
+  user_data_t cb_data;
+  struct timespec cb_interval;
+
   if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
   {
     WARNING ("snmp plugin: `Host' needs exactly one string argument.");
@@ -526,6 +581,7 @@ static int csnmp_config_add_host (oconfig_item_t *ci)
     return (-1);
   memset (hd, '\0', sizeof (host_definition_t));
   hd->version = 2;
+  C_COMPLAIN_INIT (&hd->complaint);
 
   hd->name = strdup (ci->values[0].value.string);
   if (hd->name == NULL)
@@ -535,9 +591,7 @@ static int csnmp_config_add_host (oconfig_item_t *ci)
   }
 
   hd->sess_handle = NULL;
-  hd->skip_num = 0;
-  hd->skip_left = 0;
-  hd->state = STATE_IDLE;
+  hd->interval = 0;
 
   for (i = 0; i < ci->children_num; i++)
   {
@@ -584,23 +638,30 @@ static int csnmp_config_add_host (oconfig_item_t *ci)
 
   if (status != 0)
   {
-    sfree (hd->name);
-    sfree (hd);
+    csnmp_host_definition_destroy (hd);
     return (-1);
   }
 
   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
+  ssnprintf (cb_name, sizeof (cb_name), "snmp-%s", hd->name);
+
+  memset (&cb_data, 0, sizeof (cb_data));
+  cb_data.data = hd;
+  cb_data.free_func = csnmp_host_definition_destroy;
+
+  memset (&cb_interval, 0, sizeof (cb_interval));
+  if (hd->interval != 0)
+    cb_interval.tv_sec = (time_t) hd->interval;
+
+  status = plugin_register_complex_read (cb_name, csnmp_read_host,
+      /* interval = */ &cb_interval, /* user_data = */ &cb_data);
+  if (status != 0)
   {
-    host_definition_t *last;
-    last = host_head;
-    while (last->next != NULL)
-      last = last->next;
-    last->next = hd;
+    ERROR ("snmp plugin: Registering complex read function failed.");
+    csnmp_host_definition_destroy (hd);
+    return (-1);
   }
 
   return (0);
@@ -628,30 +689,7 @@ static int csnmp_config (oconfig_item_t *ci)
   return (0);
 } /* int csnmp_config */
 
-/* End of the config stuff. Now the interesting part begins */
-
-static void csnmp_host_close_session (host_definition_t *host)
-{
-  int status;
-
-  if (host->sess_handle == NULL)
-    return;
-
-  status = snmp_sess_close (host->sess_handle);
-
-  if (status != 0)
-  {
-    char *errstr = NULL;
-
-    snmp_sess_error (host->sess_handle, NULL, NULL, &errstr);
-
-    ERROR ("snmp plugin: host %s: snmp_sess_close failed: %s",
-	host->name, (errstr == NULL) ? "Unknown problem" : errstr);
-    sfree (errstr);
-  }
-
-  host->sess_handle = NULL;
-} /* void csnmp_host_close_session */
+/* }}} End of the config stuff. Now the interesting part begins */
 
 static void csnmp_host_open_session (host_definition_t *host)
 {
@@ -681,11 +719,13 @@ static void csnmp_host_open_session (host_definition_t *host)
   }
 } /* void csnmp_host_open_session */
 
+/* TODO: Check if negative values wrap around. Problem: negative temperatures. */
 static value_t csnmp_value_list_to_value (struct variable_list *vl, int type,
     double scale, double shift)
 {
   value_t ret;
-  uint64_t temp = 0;
+  uint64_t tmp_unsigned = 0;
+  int64_t tmp_signed = 0;
   int defined = 1;
 
   if ((vl->type == ASN_INTEGER)
@@ -696,15 +736,21 @@ static value_t csnmp_value_list_to_value (struct variable_list *vl, int type,
 #endif
       || (vl->type == ASN_GAUGE))
   {
-    temp = (uint32_t) *vl->val.integer;
-    DEBUG ("snmp plugin: Parsed int32 value is %llu.", temp);
+    tmp_unsigned = (uint32_t) *vl->val.integer;
+    tmp_signed = (int32_t) *vl->val.integer;
+    DEBUG ("snmp plugin: Parsed int32 value is %"PRIi64".", tmp_signed);
   }
   else if (vl->type == ASN_COUNTER64)
   {
-    temp = (uint32_t) vl->val.counter64->high;
-    temp = temp << 32;
-    temp += (uint32_t) vl->val.counter64->low;
-    DEBUG ("snmp plugin: Parsed int64 value is %llu.", temp);
+    tmp_unsigned = (uint32_t) vl->val.counter64->high;
+    tmp_unsigned = tmp_unsigned << 32;
+    tmp_unsigned += (uint32_t) vl->val.counter64->low;
+    tmp_signed = (int64_t) tmp_unsigned;
+    DEBUG ("snmp plugin: Parsed int64 value is %"PRIu64".", tmp_unsigned);
+  }
+  else if (vl->type == ASN_OCTET_STR)
+  {
+    /* We'll handle this later.. */
   }
   else
   {
@@ -712,15 +758,74 @@ static value_t csnmp_value_list_to_value (struct variable_list *vl, int type,
     defined = 0;
   }
 
-  if (type == DS_TYPE_COUNTER)
+  if (vl->type == ASN_OCTET_STR)
+  {
+    int status = -1;
+
+    if (vl->val.string != NULL)
+    {
+      char string[64];
+      size_t string_length;
+
+      string_length = sizeof (string) - 1;
+      if (vl->val_len < string_length)
+	string_length = vl->val_len;
+
+      /* The strings we get from the Net-SNMP library may not be null
+       * terminated. That is why we're using `memcpy' here and not `strcpy'.
+       * `string_length' is set to `vl->val_len' which holds the length of the
+       * string.  -octo */
+      memcpy (string, vl->val.string, string_length);
+      string[string_length] = 0;
+
+      status = parse_value (string, &ret, type);
+      if (status != 0)
+      {
+	ERROR ("snmp plugin: csnmp_value_list_to_value: Parsing string as %s failed: %s",
+	    DS_TYPE_TO_STRING (type), string);
+      }
+    }
+
+    if (status != 0)
+    {
+      switch (type)
+      {
+	case DS_TYPE_COUNTER:
+	case DS_TYPE_DERIVE:
+	case DS_TYPE_ABSOLUTE:
+	  memset (&ret, 0, sizeof (ret));
+	  break;
+
+	case DS_TYPE_GAUGE:
+	  ret.gauge = NAN;
+	  break;
+
+	default:
+	  ERROR ("snmp plugin: csnmp_value_list_to_value: Unknown "
+	      "data source type: %i.", type);
+	  ret.gauge = NAN;
+      }
+    }
+  } /* if (vl->type == ASN_OCTET_STR) */
+  else if (type == DS_TYPE_COUNTER)
   {
-    ret.counter = temp;
+    ret.counter = tmp_unsigned;
   }
   else if (type == DS_TYPE_GAUGE)
   {
     ret.gauge = NAN;
     if (defined != 0)
-      ret.gauge = (scale * temp) + shift;
+      ret.gauge = (scale * tmp_signed) + shift;
+  }
+  else if (type == DS_TYPE_DERIVE)
+    ret.derive = (derive_t) tmp_signed;
+  else if (type == DS_TYPE_ABSOLUTE)
+    ret.absolute = (absolute_t) tmp_unsigned;
+  else
+  {
+    ERROR ("snmp plugin: csnmp_value_list_to_value: Unknown data source "
+	"type: %i.", type);
+    ret.gauge = NAN;
   }
 
   return (ret);
@@ -769,7 +874,7 @@ static int csnmp_check_res_left_subtree (const host_definition_t *host,
     if (vb == NULL)
     {
       ERROR ("snmp plugin: host %s: Expected one more variable for "
-	  "the instance..");
+	  "the instance..", host->name);
       return (-1);
     }
 
@@ -789,6 +894,72 @@ static int csnmp_check_res_left_subtree (const host_definition_t *host,
   return (0);
 } /* int csnmp_check_res_left_subtree */
 
+static int csnmp_strvbcopy_hexstring (char *dst, /* {{{ */
+    const struct variable_list *vb, size_t dst_size)
+{
+  char *buffer_ptr;
+  size_t buffer_free;
+  size_t i;
+
+  buffer_ptr = dst;
+  buffer_free = dst_size;
+
+  for (i = 0; i < vb->val_len; i++)
+  {
+    int status;
+
+    status = snprintf (buffer_ptr, buffer_free,
+	(i == 0) ? "%02x" : ":%02x", (unsigned int) vb->val.bitstring[i]);
+
+    if (status >= buffer_free)
+    {
+      buffer_ptr += (buffer_free - 1);
+      *buffer_ptr = 0;
+      return (dst_size + (buffer_free - status));
+    }
+    else /* if (status < buffer_free) */
+    {
+      buffer_ptr += status;
+      buffer_free -= status;
+    }
+  }
+
+  return ((int) (dst_size - buffer_free));
+} /* }}} int csnmp_strvbcopy_hexstring */
+
+static int csnmp_strvbcopy (char *dst, /* {{{ */
+    const struct variable_list *vb, size_t dst_size)
+{
+  char *src;
+  size_t num_chars;
+  size_t i;
+
+  if (vb->type == ASN_OCTET_STR)
+    src = (char *) vb->val.string;
+  else if (vb->type == ASN_BIT_STR)
+    src = (char *) vb->val.bitstring;
+  else
+  {
+    dst[0] = 0;
+    return (EINVAL);
+  }
+
+  num_chars = dst_size - 1;
+  if (num_chars > vb->val_len)
+    num_chars = vb->val_len;
+
+  for (i = 0; i < num_chars; i++)
+  {
+    /* Check for control characters. */
+    if ((src[i] >= 0) && (src[i] < 32))
+      return (csnmp_strvbcopy_hexstring (dst, vb, dst_size));
+    dst[i] = src[i];
+  }
+  dst[num_chars] = 0;
+
+  return ((int) vb->val_len);
+} /* }}} int csnmp_strvbcopy */
+
 static int csnmp_instance_list_add (csnmp_list_instances_t **head,
     csnmp_list_instances_t **tail,
     const struct snmp_pdu *res)
@@ -817,17 +988,8 @@ static int csnmp_instance_list_add (csnmp_list_instances_t **head,
   if ((vb->type == ASN_OCTET_STR) || (vb->type == ASN_BIT_STR))
   {
     char *ptr;
-    size_t instance_len;
-
-    instance_len = sizeof (il->instance) - 1;
-    if (instance_len > vb->val_len)
-      instance_len = vb->val_len;
 
-    strncpy (il->instance, (char *) ((vb->type == ASN_OCTET_STR)
-	  ? vb->val.string
-	  : vb->val.bitstring),
-	instance_len);
-    il->instance[instance_len] = '\0';
+    csnmp_strvbcopy (il->instance, vb, sizeof (il->instance));
 
     for (ptr = il->instance; *ptr != '\0'; ptr++)
     {
@@ -841,10 +1003,9 @@ static int csnmp_instance_list_add (csnmp_list_instances_t **head,
   else
   {
     value_t val = csnmp_value_list_to_value (vb, DS_TYPE_COUNTER, 1.0, 0.0);
-    snprintf (il->instance, sizeof (il->instance),
+    ssnprintf (il->instance, sizeof (il->instance),
 	"%llu", val.counter);
   }
-  il->instance[sizeof (il->instance) - 1] = '\0';
 
   /* TODO: Debugging output */
 
@@ -897,12 +1058,10 @@ static int csnmp_dispatch_table (host_definition_t *host, data_definition_t *dat
     return (-1);
   }
 
-  strncpy (vl.host, host->name, sizeof (vl.host));
-  vl.host[sizeof (vl.host) - 1] = '\0';
-  strcpy (vl.plugin, "snmp");
+  sstrncpy (vl.host, host->name, sizeof (vl.host));
+  sstrncpy (vl.plugin, "snmp", sizeof (vl.plugin));
 
-  vl.interval = host->skip_num;
-  vl.time = time (NULL);
+  vl.interval = host->interval;
 
   subid = 0;
   have_more = 1;
@@ -962,19 +1121,28 @@ static int csnmp_dispatch_table (host_definition_t *host, data_definition_t *dat
 	|| (instance_list_ptr->subid == value_table_ptr[0]->subid));
 #endif
 
-    if (instance_list_ptr == NULL)
-      snprintf (vl.type_instance, sizeof (vl.type_instance), "%u",
-	  (uint32_t) subid);
-    else
-      strncpy (vl.type_instance, instance_list_ptr->instance,
-	  sizeof (vl.type_instance));
-    vl.type_instance[sizeof (vl.type_instance) - 1] = '\0';
+    sstrncpy (vl.type, data->type, sizeof (vl.type));
+
+    {
+      char temp[DATA_MAX_NAME_LEN];
+
+      if (instance_list_ptr == NULL)
+	ssnprintf (temp, sizeof (temp), "%u", (uint32_t) subid);
+      else
+	sstrncpy (temp, instance_list_ptr->instance, sizeof (temp));
+
+      if (data->instance_prefix == NULL)
+	sstrncpy (vl.type_instance, temp, sizeof (vl.type_instance));
+      else
+	ssnprintf (vl.type_instance, sizeof (vl.type_instance), "%s%s",
+	    data->instance_prefix, temp);
+    }
 
     for (i = 0; i < data->values_len; i++)
       vl.values[i] = value_table_ptr[i]->value;
 
     /* If we get here `vl.type_instance' and all `vl.values' have been set */
-    plugin_dispatch_values (data->type, &vl);
+    plugin_dispatch_values (&vl);
 
     subid++;
   } /* while (have_more != 0) */
@@ -1069,18 +1237,27 @@ static int csnmp_read_table (host_definition_t *host, data_definition_t *data)
       break;
     }
 
-    for (i = 0; i < oid_list_len; i++)
+    for (i = 0; (uint32_t) i < oid_list_len; i++)
       snmp_add_null_var (req, oid_list[i].oid, oid_list[i].oid_len);
 
+    res = NULL;
     status = snmp_sess_synch_response (host->sess_handle, req, &res);
 
-    if (status != STAT_SUCCESS)
+    if ((status != STAT_SUCCESS) || (res == NULL))
     {
       char *errstr = NULL;
 
       snmp_sess_error (host->sess_handle, NULL, NULL, &errstr);
-      ERROR ("snmp plugin: host %s: snmp_sess_synch_response failed: %s",
+
+      c_complain (LOG_ERR, &host->complaint,
+	  "snmp plugin: host %s: snmp_sess_synch_response failed: %s",
 	  host->name, (errstr == NULL) ? "Unknown problem" : errstr);
+
+      if (res != NULL)
+	snmp_free_pdu (res);
+      res = NULL;
+
+      sfree (errstr);
       csnmp_host_close_session (host);
 
       status = -1;
@@ -1088,6 +1265,9 @@ static int csnmp_read_table (host_definition_t *host, data_definition_t *data)
     }
     status = 0;
     assert (res != NULL);
+    c_release (LOG_INFO, &host->complaint,
+	"snmp plugin: host %s: snmp_sess_synch_response successful.",
+	host->name);
 
     vb = res->variables;
     if (vb == NULL)
@@ -1099,7 +1279,10 @@ static int csnmp_read_table (host_definition_t *host, data_definition_t *data)
     /* Check if all values (and possibly the instance) have left their
      * subtree */
     if (csnmp_check_res_left_subtree (host, data, res) != 0)
+    {
+      status = 0;
       break;
+    }
 
     /* if an instance-OID is configured.. */
     if (data->instance.oid.oid_len > 0)
@@ -1119,11 +1302,7 @@ static int csnmp_read_table (host_definition_t *host, data_definition_t *data)
 	  (vb != NULL) && (vb->next_variable != NULL);
 	  vb = vb->next_variable)
 	/* do nothing */;
-      if (vb == NULL)
-      {
-	status = -1;
-	break;
-      }
+      assert (vb != NULL);
 
       /* Copy OID to oid_list[data->values_len] */
       memcpy (oid_list[data->values_len].oid, vb->name,
@@ -1186,6 +1365,10 @@ static int csnmp_read_table (host_definition_t *host, data_definition_t *data)
     res = NULL;
   } /* while (status == 0) */
 
+  if (res != NULL)
+    snmp_free_pdu (res);
+  res = NULL;
+
   if (status == 0)
     csnmp_dispatch_table (host, data, instance_list, value_table);
 
@@ -1261,13 +1444,12 @@ static int csnmp_read_value (host_definition_t *host, data_definition_t *data)
       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';
+  sstrncpy (vl.host, host->name, sizeof (vl.host));
+  sstrncpy (vl.plugin, "snmp", sizeof (vl.plugin));
+  sstrncpy (vl.type, data->type, sizeof (vl.type));
+  sstrncpy (vl.type_instance, data->instance.string, sizeof (vl.type_instance));
 
-  vl.interval = host->skip_num;
+  vl.interval = host->interval;
 
   req = snmp_pdu_create (SNMP_MSG_GET);
   if (req == NULL)
@@ -1279,29 +1461,37 @@ static int csnmp_read_value (host_definition_t *host, data_definition_t *data)
 
   for (i = 0; i < data->values_len; i++)
     snmp_add_null_var (req, data->values[i].oid, data->values[i].oid_len);
+
+  res = NULL;
   status = snmp_sess_synch_response (host->sess_handle, req, &res);
 
-  if (status != STAT_SUCCESS)
+  if ((status != STAT_SUCCESS) || (res == NULL))
   {
     char *errstr = NULL;
 
     snmp_sess_error (host->sess_handle, NULL, NULL, &errstr);
     ERROR ("snmp plugin: host %s: snmp_sess_synch_response failed: %s",
 	host->name, (errstr == NULL) ? "Unknown problem" : errstr);
-    csnmp_host_close_session (host);
+
+    if (res != NULL)
+      snmp_free_pdu (res);
+    res = NULL;
+
     sfree (errstr);
+    csnmp_host_close_session (host);
 
     return (-1);
   }
 
-  vl.time = time (NULL);
 
   for (vb = res->variables; vb != NULL; vb = vb->next_variable)
   {
+#if COLLECT_DEBUG
     char buffer[1024];
     snprint_variable (buffer, sizeof (buffer),
 	vb->name, vb->name_length, vb);
     DEBUG ("snmp plugin: Got this variable: %s", buffer);
+#endif /* COLLECT_DEBUG */
 
     for (i = 0; i < data->values_len; i++)
       if (snmp_oid_compare (data->values[i].oid, data->values[i].oid_len,
@@ -1310,20 +1500,34 @@ static int csnmp_read_value (host_definition_t *host, data_definition_t *data)
 	    data->scale, data->shift);
   } /* for (res->variables) */
 
-  snmp_free_pdu (res);
+  if (res != NULL)
+    snmp_free_pdu (res);
+  res = NULL;
 
-  DEBUG ("snmp plugin: -> plugin_dispatch_values (%s, &vl);", data->type);
-  plugin_dispatch_values (data->type, &vl);
+  DEBUG ("snmp plugin: -> plugin_dispatch_values (&vl);");
+  plugin_dispatch_values (&vl);
   sfree (vl.values);
 
   return (0);
 } /* int csnmp_read_value */
 
-static int csnmp_read_host (host_definition_t *host)
+static int csnmp_read_host (user_data_t *ud)
 {
+  host_definition_t *host;
+  time_t time_start;
+  time_t time_end;
+  int status;
+  int success;
   int i;
 
-  DEBUG ("snmp plugin: csnmp_read_host (%s);", host->name);
+  host = ud->data;
+
+  if (host->interval == 0)
+    host->interval = interval_g;
+
+  time_start = time (NULL);
+  DEBUG ("snmp plugin: csnmp_read_host (%s) started at %u;", host->name,
+      (unsigned int) time_start);
 
   if (host->sess_handle == NULL)
     csnmp_host_open_session (host);
@@ -1331,175 +1535,51 @@ static int csnmp_read_host (host_definition_t *host)
   if (host->sess_handle == NULL)
     return (-1);
 
+  success = 0;
   for (i = 0; i < host->data_list_len; i++)
   {
     data_definition_t *data = host->data_list[i];
 
     if (data->is_table)
-      csnmp_read_table (host, data);
+      status = csnmp_read_table (host, data);
     else
-      csnmp_read_value (host, data);
-  }
-
-  return (0);
-} /* int csnmp_read_host */
-
-static void *csnmp_read_thread (void *data)
-{
-  host_definition_t *host;
-
-  pthread_mutex_lock (&host_lock);
-  while (do_shutdown == 0)
-  {
-    pthread_cond_wait (&host_cond, &host_lock);
-
-    for (host = host_head; host != NULL; host = host->next)
-    {
-      if (do_shutdown != 0)
-	break;
-      if (host->state != STATE_WAIT)
-	continue;
+      status = csnmp_read_value (host, data);
 
-      host->state = STATE_BUSY;
-      pthread_mutex_unlock (&host_lock);
-      csnmp_read_host (host);
-      pthread_mutex_lock (&host_lock);
-      host->state = STATE_IDLE;
-    } /* for (host) */
-  } /* while (do_shutdown == 0) */
-  pthread_mutex_unlock (&host_lock);
-
-  pthread_exit ((void *) 0);
-  return ((void *) 0);
-} /* void *csnmp_read_thread */
-
-static int csnmp_init (void)
-{
-  host_definition_t *host;
-  int i;
-
-  if (host_head == NULL)
-  {
-    NOTICE ("snmp plugin: No host has been defined.");
-    return (-1);
+    if (status == 0)
+      success++;
   }
 
-  call_snmp_init_once ();
-
-  threads_num = 0;
-  for (host = host_head; host != NULL; host = host->next)
-  {
-    threads_num++;
-    /* We need to initialize `skip_num' here, because `interval_g' isn't
-     * initialized during `configure'. */
-    host->skip_left = interval_g;
-    if (host->skip_num == 0)
-    {
-      host->skip_num = interval_g;
-    }
-    else if (host->skip_num < interval_g)
-    {
-      host->skip_num = interval_g;
-      WARNING ("snmp plugin: Data for host `%s' will be collected every %i seconds.",
-	  host->name, host->skip_num);
-    }
-
-    csnmp_host_open_session (host);
-  } /* for (host) */
-
-  /* Now start the reading threads */
-  if (threads_num > 3)
+  time_end = time (NULL);
+  DEBUG ("snmp plugin: csnmp_read_host (%s) finished at %u;", host->name,
+      (unsigned int) time_end);
+  if ((uint32_t) (time_end - time_start) > host->interval)
   {
-    threads_num = 3 + ((threads_num - 3) / 10);
-    if (threads_num > 10)
-      threads_num = 10;
+    WARNING ("snmp plugin: Host `%s' should be queried every %"PRIu32
+	" seconds, but reading all values takes %u seconds.",
+	host->name, host->interval, (unsigned int) (time_end - time_start));
   }
 
-  threads = (pthread_t *) malloc (threads_num * sizeof (pthread_t));
-  if (threads == NULL)
-  {
-    ERROR ("snmp plugin: malloc failed.");
+  if (success == 0)
     return (-1);
-  }
-  memset (threads, '\0', threads_num * sizeof (pthread_t));
-
-  for (i = 0; i < threads_num; i++)
-      pthread_create (threads + i, NULL, csnmp_read_thread, (void *) 0);
 
   return (0);
-} /* int csnmp_init */
+} /* int csnmp_read_host */
 
-static int csnmp_read (void)
+static int csnmp_init (void)
 {
-  host_definition_t *host;
-  time_t now;
-
-  if (host_head == NULL)
-  {
-    INFO ("snmp plugin: No hosts configured.");
-    return (-1);
-  }
-
-  now = time (NULL);
-
-  pthread_mutex_lock (&host_lock);
-  for (host = host_head; host != NULL; host = host->next)
-  {
-    if (host->state != STATE_IDLE)
-      continue;
-
-    host->skip_left -= interval_g;
-    if (host->skip_left >= interval_g)
-      continue;
-
-    host->state = STATE_WAIT;
-
-    host->skip_left = host->skip_num;
-  } /* for (host) */
-
-  pthread_cond_broadcast (&host_cond);
-  pthread_mutex_unlock (&host_lock);
+  call_snmp_init_once ();
 
   return (0);
-} /* int csnmp_read */
+} /* int csnmp_init */
 
 static int csnmp_shutdown (void)
 {
-  host_definition_t *host_this;
-  host_definition_t *host_next;
-
   data_definition_t *data_this;
   data_definition_t *data_next;
 
-  int i;
-
-  pthread_mutex_lock (&host_lock);
-  do_shutdown = 1;
-  pthread_cond_broadcast (&host_cond);
-  pthread_mutex_unlock (&host_lock);
-
-  for (i = 0; i < threads_num; i++)
-    pthread_join (threads[i], NULL);
-
-  /* Now that all the threads have exited, let's free all the global variables.
-   * This isn't really neccessary, I guess, but I think it's good stile to do
-   * so anyway. */
-  host_this = host_head;
-  host_head = NULL;
-  while (host_this != NULL)
-  {
-    host_next = host_this->next;
-
-    csnmp_host_close_session (host_this);
-
-    sfree (host_this->name);
-    sfree (host_this->address);
-    sfree (host_this->community);
-    sfree (host_this->data_list);
-    sfree (host_this);
-
-    host_this = host_next;
-  }
+  /* When we get here, the read threads have been stopped and all the
+   * `host_definition_t' will be freed. */
+  DEBUG ("snmp plugin: Destroying all data definitions.");
 
   data_this = data_head;
   data_head = NULL;
@@ -1522,10 +1602,9 @@ void module_register (void)
 {
   plugin_register_complex_config ("snmp", csnmp_config);
   plugin_register_init ("snmp", csnmp_init);
-  plugin_register_read ("snmp", csnmp_read);
   plugin_register_shutdown ("snmp", csnmp_shutdown);
 } /* void module_register */
 
 /*
- * vim: shiftwidth=2 softtabstop=2 tabstop=8
+ * vim: shiftwidth=2 softtabstop=2 tabstop=8 fdm=marker
  */