Code

Merge remote-tracking branch 'github/pr/387'
[collectd.git] / src / openvpn.c
index 9f386f0da865b893efbebee2edb15a592fcadb2d..9ce23b4f4cb9c9e2550e86d337a866a451931404 100644 (file)
@@ -1,7 +1,9 @@
 /**
  * collectd - src/openvpn.c
- * Copyright (C) 2008  Doug MacEachern
- * Copyright (C) 2009  Florian octo Forster
+ * Copyright (C) 2008       Doug MacEachern
+ * Copyright (C) 2009,2010  Florian octo Forster
+ * Copyright (C) 2009       Marco Chiappero
+ * Copyright (C) 2009       Fabian Schuh
  *
  * 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
  *
  * Authors:
  *   Doug MacEachern <dougm at hyperic.com>
- *   Florian octo Forster <octo at verplant.org>
+ *   Florian octo Forster <octo at collectd.org>
+ *   Marco Chiappero <marco at absence.it>
+ *   Fabian Schuh <mail at xeroc.org>
  **/
 
 #include "collectd.h"
 #include "common.h"
 #include "plugin.h"
 
-#define DEFAULT_STATUS_FILE "/etc/openvpn/openvpn-status.log"
-#define CLIENT_LIST_PREFIX  "CLIENT_LIST,"
+#define V1STRING "Common Name,Real Address,Bytes Received,Bytes Sent,Connected Since\n"
+#define V2STRING "HEADER,CLIENT_LIST,Common Name,Real Address,Virtual Address,Bytes Received,Bytes Sent,Connected Since,Connected Since (time_t)\n"
+#define V3STRING "HEADER CLIENT_LIST Common Name Real Address Virtual Address Bytes Received Bytes Sent Connected Since Connected Since (time_t)\n"
+#define VSSTRING "OpenVPN STATISTICS\n"
 
-static char *status_file = NULL;
 
-/* For compression stats we need to convert these counters to a rate. */
-static counter_t pre_compress_old    = 0;
-static counter_t post_compress_old   = 0;
-static counter_t pre_decompress_old  = 0;
-static counter_t post_decompress_old = 0;
-static int compression_counter_valid = 0;
+struct vpn_status_s
+{
+       char *file;
+       enum
+       {
+               MULTI1 = 1, /* status-version 1 */
+               MULTI2,     /* status-version 2 */
+               MULTI3,     /* status-version 3 */
+               SINGLE = 10 /* currently no versions for single mode, maybe in the future */
+       } version;
+       char *name;
+};
+typedef struct vpn_status_s vpn_status_t;
+
+static vpn_status_t **vpn_list = NULL;
+static int vpn_num = 0;
+
+static _Bool new_naming_schema = 0;
+static _Bool collect_compression = 1;
+static _Bool collect_user_count  = 0;
+static _Bool collect_individual_users  = 1;
 
 static const char *config_keys[] =
 {
-       "StatusFile"
+       "StatusFile",
+       "Compression", /* old, deprecated name */
+       "ImprovedNamingSchema",
+       "CollectCompression",
+       "CollectUserCount",
+       "CollectIndividualUsers"
 };
 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
-/* copy-n-pasted from common.c - changed delim to "," */
+
+/* Helper function
+ * copy-n-pasted from common.c - changed delim to ","  */
 static int openvpn_strsplit (char *string, char **fields, size_t size)
 {
-        size_t i;
-        char *ptr;
-        char *saveptr;
-
-        i = 0;
-        ptr = string;
-        saveptr = NULL;
-        while ((fields[i] = strtok_r (ptr, ",", &saveptr)) != NULL)
-        {
-                ptr = NULL;
-                i++;
+       size_t i;
+       char *ptr;
+       char *saveptr;
+
+       i = 0;
+       ptr = string;
+       saveptr = NULL;
+       while ((fields[i] = strtok_r (ptr, ",", &saveptr)) != NULL)
+       {
+               ptr = NULL;
+               i++;
 
-                if (i >= size)
-                        break;
-        }
+               if (i >= size)
+                       break;
+       }
 
-        return (i);
+       return (i);
 } /* int openvpn_strsplit */
 
-static void openvpn_submit (char *name, counter_t rx, counter_t tx)
+/* dispatches number of users */
+static void numusers_submit (char *pinst, char *tinst, gauge_t value)
+{
+       value_t values[1];
+       value_list_t vl = VALUE_LIST_INIT;
+
+       values[0].gauge = value;
+
+       vl.values = values;
+       vl.values_len = STATIC_ARRAY_SIZE (values);
+       sstrncpy (vl.host, hostname_g, sizeof (vl.host));
+       sstrncpy (vl.plugin, "openvpn", sizeof (vl.plugin));
+       sstrncpy (vl.type, "users", sizeof (vl.type));
+       if (pinst != NULL)
+               sstrncpy (vl.plugin_instance, pinst, sizeof (vl.plugin_instance));
+       if (tinst != NULL)
+               sstrncpy (vl.type_instance, tinst, sizeof (vl.type_instance));
+
+       plugin_dispatch_values (&vl);
+} /* void numusers_submit */
+
+/* dispatches stats about traffic (TCP or UDP) generated by the tunnel per single endpoint */
+static void iostats_submit (char *pinst, char *tinst, derive_t rx, derive_t tx)
 {
        value_t values[2];
        value_list_t vl = VALUE_LIST_INIT;
 
-       values[0].counter = rx;
-       values[1].counter = tx;
+       values[0].derive = rx;
+       values[1].derive = tx;
+
+       /* NOTE ON THE NEW NAMING SCHEMA:
+        *       using plugin_instance to identify each vpn config (and
+        *       status) file; using type_instance to identify the endpoint
+        *       host when in multimode, traffic or overhead when in single.
+        */
 
        vl.values = values;
        vl.values_len = STATIC_ARRAY_SIZE (values);
        sstrncpy (vl.host, hostname_g, sizeof (vl.host));
        sstrncpy (vl.plugin, "openvpn", sizeof (vl.plugin));
-       sstrncpy (vl.plugin_instance, name, sizeof (vl.plugin_instance));
+       if (pinst != NULL)
+               sstrncpy (vl.plugin_instance, pinst,
+                               sizeof (vl.plugin_instance));
        sstrncpy (vl.type, "if_octets", sizeof (vl.type));
+       if (tinst != NULL)
+               sstrncpy (vl.type_instance, tinst, sizeof (vl.type_instance));
 
        plugin_dispatch_values (&vl);
-} /* void openvpn_submit */
+} /* void traffic_submit */
 
-static void compression_submit (char *type_instance, gauge_t ratio)
+/* dispatches stats about data compression shown when in single mode */
+static void compression_submit (char *pinst, char *tinst,
+               derive_t uncompressed, derive_t compressed)
 {
-       value_t values[1];
+       value_t values[2];
        value_list_t vl = VALUE_LIST_INIT;
 
-       values[0].gauge = ratio;
+       values[0].derive = uncompressed;
+       values[1].derive = compressed;
 
        vl.values = values;
        vl.values_len = STATIC_ARRAY_SIZE (values);
        sstrncpy (vl.host, hostname_g, sizeof (vl.host));
        sstrncpy (vl.plugin, "openvpn", sizeof (vl.plugin));
-       sstrncpy (vl.type, "compression_ratio", sizeof (vl.type));
-       sstrncpy (vl.type_instance, type_instance, sizeof (vl.type));
+       if (pinst != NULL)
+               sstrncpy (vl.plugin_instance, pinst,
+                               sizeof (vl.plugin_instance));
+       sstrncpy (vl.type, "compression", sizeof (vl.type));
+       if (tinst != NULL)
+               sstrncpy (vl.type_instance, tinst, sizeof (vl.type_instance));
 
        plugin_dispatch_values (&vl);
 } /* void compression_submit */
 
-static int openvpn_read (void)
+static int single_read (char *name, FILE *fh)
 {
-       FILE *fh;
        char buffer[1024];
-       char *fields[10];
+       char *fields[4];
        const int max_fields = STATIC_ARRAY_SIZE (fields);
-       int   fields_num;
+       int  fields_num, read = 0;
+
+       derive_t link_rx, link_tx;
+       derive_t tun_rx, tun_tx;
+       derive_t pre_compress, post_compress;
+       derive_t pre_decompress, post_decompress;
+       derive_t overhead_rx, overhead_tx;
+
+       link_rx = 0;
+       link_tx = 0;
+       tun_rx = 0;
+       tun_tx = 0;
+       pre_compress = 0;
+       post_compress = 0;
+       pre_decompress = 0;
+       post_decompress = 0;
+       overhead_rx = 0;
+       overhead_tx = 0;
 
-       counter_t pre_compress_new    = 0;
-       counter_t post_compress_new   = 0;
-       counter_t pre_decompress_new  = 0;
-       counter_t post_decompress_new = 0;
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
+       {
+               fields_num = openvpn_strsplit (buffer, fields, max_fields);
 
-       /* Clear the least significant four bits, just to make sure all four
-        * counters above are considered to be invalid. */
-       compression_counter_valid &= ~0x0f;
+               /* status file is generated by openvpn/sig.c:print_status()
+                * http://svn.openvpn.net/projects/openvpn/trunk/openvpn/sig.c
+                *
+                * The line we're expecting has 2 fields. We ignore all lines
+                *  with more or less fields.
+                */
+               if (fields_num != 2)
+               {
+                       continue;
+               }
 
-       fh = fopen ((status_file != NULL)
-                       ? status_file
-                       : DEFAULT_STATUS_FILE, "r");
-       if (fh == NULL)
-               return (-1);
+               if (strcmp (fields[0], "TUN/TAP read bytes") == 0)
+               {
+                       /* read from the system and sent over the tunnel */
+                       tun_tx = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "TUN/TAP write bytes") == 0)
+               {
+                       /* read from the tunnel and written in the system */
+                       tun_rx = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "TCP/UDP read bytes") == 0)
+               {
+                       link_rx = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "TCP/UDP write bytes") == 0)
+               {
+                       link_tx = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "pre-compress bytes") == 0)
+               {
+                       pre_compress = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "post-compress bytes") == 0)
+               {
+                       post_compress = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "pre-decompress bytes") == 0)
+               {
+                       pre_decompress = atoll (fields[1]);
+               }
+               else if (strcmp (fields[0], "post-decompress bytes") == 0)
+               {
+                       post_decompress = atoll (fields[1]);
+               }
+       }
 
-        /* status file is generated by openvpn/multi.c:multi_print_status()
-        * this plugin requires server.conf: "status-version 2"
-         * http://svn.openvpn.net/projects/openvpn/trunk/openvpn/multi.c
-         */
+       iostats_submit (name, "traffic", link_rx, link_tx);
+
+       /* we need to force this order to avoid negative values with these unsigned */
+       overhead_rx = (((link_rx - pre_decompress) + post_decompress) - tun_rx);
+       overhead_tx = (((link_tx - post_compress) + pre_compress) - tun_tx);
+
+       iostats_submit (name, "overhead", overhead_rx, overhead_tx);
+
+       if (collect_compression)
+       {
+               compression_submit (name, "data_in", post_decompress, pre_decompress);
+               compression_submit (name, "data_out", pre_compress, post_compress);
+       }
+
+       read = 1;
+
+       return (read);
+} /* int single_read */
+
+/* for reading status version 1 */
+static int multi1_read (char *name, FILE *fh)
+{
+       char buffer[1024];
+       char *fields[10];
+       int  fields_num, read = 0, found_header = 0;
+       long long sum_users = 0;
+
+       /* read the file until the "ROUTING TABLE" line is found (no more info after) */
        while (fgets (buffer, sizeof (buffer), fh) != NULL)
        {
-               fields_num = openvpn_strsplit (buffer, fields, max_fields);
+               if (strcmp (buffer, "ROUTING TABLE\n") == 0)
+                       break;
 
-               /* Expect at least ``key,value''. */
-               if (fields_num < 2)
+               if (strcmp (buffer, V1STRING) == 0)
+               {
+                       found_header = 1;
                        continue;
+               }
 
-               if (strcmp (fields[0], "CLIENT_LIST") == 0)
-               {
-                       char *name;
-                       counter_t rx;
-                       counter_t tx;
+               /* skip the first lines until the client list section is found */
+               if (found_header == 0)
+                       /* we can't start reading data until this string is found */
+                       continue;
 
-                       /* The line we're expecting has 8 fields. We ignore all lines
-                        * with more or less fields. */
-                       if (fields_num != 8)
-                               continue;
+               fields_num = openvpn_strsplit (buffer,
+                               fields, STATIC_ARRAY_SIZE (fields));
+               if (fields_num < 4)
+                       continue;
 
-                       name =      fields[1];  /* "Common Name" */
-                       rx = atoll (fields[4]); /* "Bytes Received */
-                       tx = atoll (fields[5]); /* "Bytes Sent" */
-                       openvpn_submit (name, rx, tx);
+               if (collect_user_count)
+                       /* If so, sum all users, ignore the individuals*/
+               {
+                       sum_users += 1;
                }
-               else if (strcmp (fields[0], "pre-compress") == 0)
+               if (collect_individual_users)
                {
-                       pre_compress_new = atoll (fields[1]);
-                       compression_counter_valid |= 0x01;
+                       if (new_naming_schema)
+                       {
+                               iostats_submit (name,               /* vpn instance */
+                                               fields[0],          /* "Common Name" */
+                                               atoll (fields[2]),  /* "Bytes Received" */
+                                               atoll (fields[3])); /* "Bytes Sent" */
+                       }
+                       else
+                       {
+                               iostats_submit (fields[0],          /* "Common Name" */
+                                               NULL,               /* unused when in multimode */
+                                               atoll (fields[2]),  /* "Bytes Received" */
+                                               atoll (fields[3])); /* "Bytes Sent" */
+                       }
                }
-               else if (strcmp (fields[0], "post-compress") == 0)
+
+               read = 1;
+       }
+
+       if (collect_user_count)
+       {
+               numusers_submit(name, name, sum_users);
+               read = 1;
+       }
+
+       return (read);
+} /* int multi1_read */
+
+/* for reading status version 2 */
+static int multi2_read (char *name, FILE *fh)
+{
+       char buffer[1024];
+       char *fields[10];
+       const int max_fields = STATIC_ARRAY_SIZE (fields);
+       int  fields_num, read = 0;
+       long long sum_users    = 0;
+
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
+       {
+               fields_num = openvpn_strsplit (buffer, fields, max_fields);
+
+               /* status file is generated by openvpn/multi.c:multi_print_status()
+                * http://svn.openvpn.net/projects/openvpn/trunk/openvpn/multi.c
+                *
+                * The line we're expecting has 8 fields. We ignore all lines
+                *  with more or less fields.
+                */
+               if (fields_num != 8)
+                       continue;
+
+               if (strcmp (fields[0], "CLIENT_LIST") != 0)
+                       continue;
+
+               if (collect_user_count)
+                       /* If so, sum all users, ignore the individuals*/
                {
-                       post_compress_new = atoll (fields[1]);
-                       compression_counter_valid |= 0x02;
+                       sum_users += 1;
                }
-               else if (strcmp (fields[0], "pre-decompress") == 0)
+               if (collect_individual_users)
                {
-                       pre_decompress_new = atoll (fields[1]);
-                       compression_counter_valid |= 0x04;
+                       if (new_naming_schema)
+                       {
+                               /* plugin inst = file name, type inst = fields[1] */
+                               iostats_submit (name,               /* vpn instance */
+                                               fields[1],          /* "Common Name" */
+                                               atoll (fields[4]),  /* "Bytes Received" */
+                                               atoll (fields[5])); /* "Bytes Sent" */
+                       }
+                       else
+                       {
+                               /* plugin inst = fields[1], type inst = "" */
+                               iostats_submit (fields[1],          /* "Common Name" */
+                                               NULL,               /* unused when in multimode */
+                                               atoll (fields[4]),  /* "Bytes Received" */
+                                               atoll (fields[5])); /* "Bytes Sent" */
+                       }
                }
-               else if (strcmp (fields[0], "post-decompress") == 0)
+
+               read = 1;
+       }
+
+       if (collect_user_count)
+       {
+               numusers_submit(name, name, sum_users);
+               read = 1;
+       }
+
+       return (read);
+} /* int multi2_read */
+
+/* for reading status version 3 */
+static int multi3_read (char *name, FILE *fh)
+{
+       char buffer[1024];
+       char *fields[15];
+       const int max_fields = STATIC_ARRAY_SIZE (fields);
+       int  fields_num, read = 0;
+       long long sum_users    = 0;
+
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
+       {
+               fields_num = strsplit (buffer, fields, max_fields);
+
+               /* status file is generated by openvpn/multi.c:multi_print_status()
+                * http://svn.openvpn.net/projects/openvpn/trunk/openvpn/multi.c
+                *
+                * The line we're expecting has 12 fields. We ignore all lines
+                *  with more or less fields.
+                */
+               if (fields_num != 12)
                {
-                       post_decompress_new = atoll (fields[1]);
-                       compression_counter_valid |= 0x08;
+                       continue;
+               }
+               else
+               {
+                       if (strcmp (fields[0], "CLIENT_LIST") != 0)
+                               continue;
+
+                       if (collect_user_count)
+                               /* If so, sum all users, ignore the individuals*/
+                       {
+                               sum_users += 1;
+                       }
+
+                       if (collect_individual_users)
+                       {
+                               if (new_naming_schema)
+                               {
+                                       iostats_submit (name,               /* vpn instance */
+                                                       fields[1],          /* "Common Name" */
+                                                       atoll (fields[4]),  /* "Bytes Received" */
+                                                       atoll (fields[5])); /* "Bytes Sent" */
+                               }
+                               else
+                               {
+                                       iostats_submit (fields[1],          /* "Common Name" */
+                                                       NULL,               /* unused when in multimode */
+                                                       atoll (fields[4]),  /* "Bytes Received" */
+                                                       atoll (fields[5])); /* "Bytes Sent" */
+                               }
+                       }
+
+                       read = 1;
                }
        }
-       fclose (fh);
 
-       /* Check that all four counters are valid, {pre,post}_*_{old,new}. */
-       if ((compression_counter_valid & 0x33) == 0x33)
+       if (collect_user_count)
+       {
+               numusers_submit(name, name, sum_users);
+               read = 1;
+       }
+
+       return (read);
+} /* int multi3_read */
+
+/* read callback */
+static int openvpn_read (void)
+{
+       FILE *fh;
+       int  i, read;
+
+       read = 0;
+
+       /* call the right read function for every status entry in the list */
+       for (i = 0; i < vpn_num; i++)
        {
-               counter_t pre_diff;
-               counter_t post_diff;
+               fh = fopen (vpn_list[i]->file, "r");
+               if (fh == NULL)
+               {
+                       char errbuf[1024];
+                       WARNING ("openvpn plugin: fopen(%s) failed: %s", vpn_list[i]->file,
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
 
-               pre_diff = counter_diff (pre_compress_old, pre_compress_new);
-               post_diff = counter_diff (post_compress_old, post_compress_new);
+                       continue;
+               }
+
+               switch (vpn_list[i]->version)
+               {
+                       case SINGLE:
+                               read = single_read(vpn_list[i]->name, fh);
+                               break;
+
+                       case MULTI1:
+                               read = multi1_read(vpn_list[i]->name, fh);
+                               break;
+
+                       case MULTI2:
+                               read = multi2_read(vpn_list[i]->name, fh);
+                               break;
+
+                       case MULTI3:
+                               read = multi3_read(vpn_list[i]->name, fh);
+                               break;
+               }
 
-               /* If we compress, we're sending. */
-               compression_submit ("tx",
-                               ((gauge_t) post_diff) / ((gauge_t) pre_diff));
+               fclose (fh);
        }
 
-       /* Now check the other found counters. */
-       if ((compression_counter_valid & 0xcc) == 0xcc)
+       return (read ? 0 : -1);
+} /* int openvpn_read */
+
+static int version_detect (const char *filename)
+{
+       FILE *fh;
+       char buffer[1024];
+       int version = 0;
+
+       /* Sanity checking. We're called from the config handling routine, so
+        * better play it save. */
+       if ((filename == NULL) || (*filename == 0))
+               return (0);
+
+       fh = fopen (filename, "r");
+       if (fh == NULL)
        {
-               counter_t pre_diff;
-               counter_t post_diff;
+               char errbuf[1024];
+               WARNING ("openvpn plugin: Unable to read \"%s\": %s", filename,
+                               sstrerror (errno, errbuf, sizeof (errbuf)));
+               return (0);
+       }
 
-               pre_diff = counter_diff (pre_decompress_old, pre_decompress_new);
-               post_diff = counter_diff (post_decompress_old, post_decompress_new);
+       /* now search for the specific multimode data format */
+       while ((fgets (buffer, sizeof (buffer), fh)) != NULL)
+       {
+               /* we look at the first line searching for SINGLE mode configuration */
+               if (strcmp (buffer, VSSTRING) == 0)
+               {
+                       DEBUG ("openvpn plugin: found status file version SINGLE");
+                       version = SINGLE;
+                       break;
+               }
+               /* searching for multi version 1 */
+               else if (strcmp (buffer, V1STRING) == 0)
+               {
+                       DEBUG ("openvpn plugin: found status file version MULTI1");
+                       version = MULTI1;
+                       break;
+               }
+               /* searching for multi version 2 */
+               else if (strcmp (buffer, V2STRING) == 0)
+               {
+                       DEBUG ("openvpn plugin: found status file version MULTI2");
+                       version = MULTI2;
+                       break;
+               }
+               /* searching for multi version 3 */
+               else if (strcmp (buffer, V3STRING) == 0)
+               {
+                       DEBUG ("openvpn plugin: found status file version MULTI3");
+                       version = MULTI3;
+                       break;
+               }
+       }
 
-               /* If we decompress, we're receiving. */
-               compression_submit ("rx",
-                               ((gauge_t) pre_diff) / ((gauge_t) post_diff));
+       if (version == 0)
+       {
+               /* This is only reached during configuration, so complaining to
+                * the user is in order. */
+               NOTICE ("openvpn plugin: %s: Unknown file format, please "
+                               "report this as bug. Make sure to include "
+                               "your status file, so the plugin can "
+                               "be adapted.", filename);
        }
 
-       /* Now copy all the new counters to the old counters and move the flags
-        * up. */
-       pre_compress_old = pre_compress_new;
-       post_compress_old = post_compress_new;
-       pre_decompress_old = pre_decompress_new;
-       post_decompress_old = post_decompress_new;
-       compression_counter_valid = (compression_counter_valid & 0x0f) << 4;
+       fclose (fh);
 
-       return (0);
-} /* int openvpn_read */
+       return version;
+} /* int version_detect */
 
 static int openvpn_config (const char *key, const char *value)
 {
        if (strcasecmp ("StatusFile", key) == 0)
        {
-               sfree (status_file);
+               char    *status_file, *status_name, *filename;
+               int     status_version, i;
+               vpn_status_t *temp;
+
+               /* try to detect the status file format */
+               status_version = version_detect (value);
+
+               if (status_version == 0)
+               {
+                       WARNING ("openvpn plugin: unable to detect status version, \
+                                       discarding status file \"%s\".", value);
+                       return (1);
+               }
+
                status_file = sstrdup (value);
-       }
+               if (status_file == NULL)
+               {
+                       char errbuf[1024];
+                       WARNING ("openvpn plugin: sstrdup failed: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+                       return (1);
+               }
+
+               /* it determines the file name as string starting at location filename + 1 */
+               filename = strrchr (status_file, (int) '/');
+               if (filename == NULL)
+               {
+                       /* status_file is already the file name only */
+                       status_name = status_file;
+               }
+               else
+               {
+                       /* doesn't waste memory, uses status_file starting at filename + 1 */
+                       status_name = filename + 1;
+               }
+
+               /* scan the list looking for a clone */
+               for (i = 0; i < vpn_num; i++)
+               {
+                       if (strcasecmp (vpn_list[i]->name, status_name) == 0)
+                       {
+                               WARNING ("openvpn plugin: status filename \"%s\" "
+                                               "already used, please choose a "
+                                               "different one.", status_name);
+                               sfree (status_file);
+                               return (1);
+                       }
+               }
+
+               /* create a new vpn element since file, version and name are ok */
+               temp = (vpn_status_t *) malloc (sizeof (vpn_status_t));
+               temp->file = status_file;
+               temp->version = status_version;
+               temp->name = status_name;
+
+               vpn_list = (vpn_status_t **) realloc (vpn_list, (vpn_num + 1) * sizeof (vpn_status_t *));
+               if (vpn_list == NULL)
+               {
+                       char errbuf[1024];
+                       ERROR ("openvpn plugin: malloc failed: %s",
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+
+                       sfree (temp->file);
+                       sfree (temp);
+                       return (1);
+               }
+
+               vpn_list[vpn_num] = temp;
+               vpn_num++;
+
+               DEBUG ("openvpn plugin: status file \"%s\" added", temp->file);
+
+       } /* if (strcasecmp ("StatusFile", key) == 0) */
+       else if ((strcasecmp ("CollectCompression", key) == 0)
+               || (strcasecmp ("Compression", key) == 0)) /* old, deprecated name */
+       {
+               if (IS_FALSE (value))
+                       collect_compression = 0;
+               else
+                       collect_compression = 1;
+       } /* if (strcasecmp ("CollectCompression", key) == 0) */
+       else if (strcasecmp ("ImprovedNamingSchema", key) == 0)
+       {
+               if (IS_TRUE (value))
+               {
+                       DEBUG ("openvpn plugin: using the new naming schema");
+                       new_naming_schema = 1;
+               }
+               else
+               {
+                       new_naming_schema = 0;
+               }
+       } /* if (strcasecmp ("ImprovedNamingSchema", key) == 0) */
+       else if (strcasecmp("CollectUserCount", key) == 0)
+       {
+               if (IS_TRUE(value))
+                       collect_user_count = 1;
+               else
+                       collect_user_count = 0;
+       } /* if (strcasecmp("CollectUserCount", key) == 0) */
+       else if (strcasecmp("CollectIndividualUsers", key) == 0)
+       {
+               if (IS_FALSE (value))
+                       collect_individual_users = 0;
+               else
+                       collect_individual_users = 1;
+       } /* if (strcasecmp("CollectIndividualUsers", key) == 0) */
        else
        {
                return (-1);
        }
-        return (0);
+
+       return (0);
 } /* int openvpn_config */
 
+/* shutdown callback */
+static int openvpn_shutdown (void)
+{
+       int i;
+
+       for (i = 0; i < vpn_num; i++)
+       {
+               sfree (vpn_list[i]->file);
+               sfree (vpn_list[i]);
+       }
+
+       sfree (vpn_list);
+
+       return (0);
+} /* int openvpn_shutdown */
+
+static int openvpn_init (void)
+{
+       if (!collect_individual_users
+                       && !collect_compression
+                       && !collect_user_count)
+       {
+               WARNING ("OpenVPN plugin: Neither `CollectIndividualUsers', "
+                               "`CollectCompression', nor `CollectUserCount' is true. There's no "
+                               "data left to collect.");
+               return (-1);
+       }
+
+       plugin_register_read ("openvpn", openvpn_read);
+       plugin_register_shutdown ("openvpn", openvpn_shutdown);
+
+       return (0);
+} /* int openvpn_init */
+
 void module_register (void)
 {
        plugin_register_config ("openvpn", openvpn_config,
-                               config_keys, config_keys_num);
-       plugin_register_read ("openvpn", openvpn_read);
+                       config_keys, config_keys_num);
+       plugin_register_init ("openvpn", openvpn_init);
 } /* void module_register */
+
+/* vim: set sw=2 ts=2 : */