X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fnetwork.c;h=a659189f3e7960d312d0d608f9f8af55d1e3c5bb;hb=acbd25344a59c091b087311804d375b759077e32;hp=4516331e9096507ae12eeb89c670d2ee242c58a6;hpb=634504760b46b852ec2b812a7b68277e9c005f1b;p=collectd.git

diff --git a/src/network.c b/src/network.c
index 4516331e..a659189f 100644
--- a/src/network.c
+++ b/src/network.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/network.c
- * Copyright (C) 2005,2006  Florian octo Forster
+ * Copyright (C) 2005-2007  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
@@ -23,7 +23,7 @@
 #include "plugin.h"
 #include "common.h"
 #include "configfile.h"
-#include "utils_debug.h"
+#include "utils_avltree.h"
 
 #include "network.h"
 
@@ -57,7 +57,7 @@
 # endif
 #endif /* !IP_ADD_MEMBERSHIP */
 
-#define BUFF_SIZE 4096
+#define BUFF_SIZE 1024
 
 /*
  * Private data types
@@ -98,6 +98,21 @@ struct part_string_s
 };
 typedef struct part_string_s part_string_t;
 
+/*                      1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-------------------------------+-------------------------------+
+ * ! Type                          ! Length                        !
+ * +-------------------------------+-------------------------------+
+ * : (Length - 4 == 2 || 4 || 8) Bytes                             :
+ * +---------------------------------------------------------------+
+ */
+struct part_number_s
+{
+	part_header_t *head;
+	uint64_t *value;
+};
+typedef struct part_number_s part_number_t;
+
 /*                      1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  * +-------------------------------+-------------------------------+
@@ -126,14 +141,16 @@ typedef struct part_values_s part_values_t;
  */
 static const char *config_keys[] =
 {
+	"CacheFlush",
 	"Listen",
 	"Server",
 	"TimeToLive",
-	NULL
+	"Forward"
 };
-static int config_keys_num = 3;
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
 static int network_config_ttl = 0;
+static int network_config_forward = 0;
 
 static sockent_t *sending_sockets = NULL;
 
@@ -142,9 +159,135 @@ static int listen_sockets_num = 0;
 static pthread_t listen_thread = 0;
 static int listen_loop = 0;
 
+static char         send_buffer[BUFF_SIZE];
+static char        *send_buffer_ptr;
+static int          send_buffer_fill;
+static value_list_t send_buffer_vl = VALUE_LIST_STATIC;
+static char         send_buffer_type[DATA_MAX_NAME_LEN];
+static pthread_mutex_t send_buffer_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static avl_tree_t      *cache_tree = NULL;
+static pthread_mutex_t  cache_lock = PTHREAD_MUTEX_INITIALIZER;
+static time_t           cache_flush_last;
+static int              cache_flush_interval = 1800;
+
 /*
  * Private functions
  */
+static int cache_flush (void)
+{
+	char **keys = NULL;
+	int    keys_num = 0;
+
+	char **tmp;
+	int    i;
+
+	char   *key;
+	time_t *value;
+	avl_iterator_t *iter;
+
+	time_t curtime = time (NULL);
+
+	iter = avl_get_iterator (cache_tree);
+	while (avl_iterator_next (iter, (void *) &key, (void *) &value) == 0)
+	{
+		if ((curtime - *value) <= cache_flush_interval)
+			continue;
+		tmp = (char **) realloc (keys,
+				(keys_num + 1) * sizeof (char *));
+		if (tmp == NULL)
+		{
+			sfree (keys);
+			avl_iterator_destroy (iter);
+			ERROR ("network plugin: cache_flush: realloc"
+					" failed.");
+			return (-1);
+		}
+		keys = tmp;
+		keys[keys_num] = key;
+		keys_num++;
+	} /* while (avl_iterator_next) */
+	avl_iterator_destroy (iter);
+
+	for (i = 0; i < keys_num; i++)
+	{
+		if (avl_remove (cache_tree, keys[i], (void *) &key,
+					(void *) &value) != 0)
+		{
+			WARNING ("network plugin: cache_flush: avl_remove"
+					" (%s) failed.", keys[i]);
+			continue;
+		}
+
+		sfree (key);
+		sfree (value);
+	}
+
+	sfree (keys);
+
+	DEBUG ("network plugin: cache_flush: Removed %i %s",
+			keys_num, (keys_num == 1) ? "entry" : "entries");
+	cache_flush_last = curtime;
+	return (0);
+} /* int cache_flush */
+
+static int cache_check (const char *type, const value_list_t *vl)
+{
+	char key[1024];
+	time_t *value = NULL;
+	int retval = -1;
+
+	if (cache_tree == NULL)
+		return (-1);
+
+	if (format_name (key, sizeof (key), vl->host, vl->plugin,
+				vl->plugin_instance, type, vl->type_instance))
+		return (-1);
+
+	pthread_mutex_lock (&cache_lock);
+
+	if (avl_get (cache_tree, key, (void *) &value) == 0)
+	{
+		if (*value < vl->time)
+		{
+			*value = vl->time;
+			retval = 0;
+		}
+		else
+		{
+			DEBUG ("network plugin: cache_check: *value = %i >= vl->time = %i",
+					(int) *value, (int) vl->time);
+			retval = 1;
+		}
+	}
+	else
+	{
+		char *key_copy = strdup (key);
+		value = malloc (sizeof (time_t));
+		if ((key_copy != NULL) && (value != NULL))
+		{
+			*value = vl->time;
+			avl_insert (cache_tree, key_copy, value);
+			retval = 0;
+		}
+		else
+		{
+			sfree (key_copy);
+			sfree (value);
+		}
+	}
+
+	if ((time (NULL) - cache_flush_last) > cache_flush_interval)
+		cache_flush ();
+
+	pthread_mutex_unlock (&cache_lock);
+
+	DEBUG ("network plugin: cache_check: key = %s; time = %i; retval = %i",
+			key, (int) vl->time, retval);
+
+	return (retval);
+} /* int cache_check */
+
 static int write_part_values (char **ret_buffer, int *ret_buffer_len,
 		const data_set_t *ds, const value_list_t *vl)
 {
@@ -183,15 +326,33 @@ static int write_part_values (char **ret_buffer, int *ret_buffer_len,
 	return (0);
 } /* int write_part_values */
 
+static int write_part_number (char **ret_buffer, int *ret_buffer_len,
+		int type, uint64_t value)
+{
+	part_number_t pn;
+
+	if (*ret_buffer_len < 12)
+		return (-1);
+
+	pn.head = (part_header_t *) *ret_buffer;
+	pn.value = (uint64_t *) (pn.head + 1);
+
+	pn.head->type = htons (type);
+	pn.head->length = htons (12);
+	*pn.value = htonll (value);
+
+	*ret_buffer = (char *) (pn.value + 1);
+	*ret_buffer_len -= 12;
+
+	return (0);
+} /* int write_part_number */
+
 static int write_part_string (char **ret_buffer, int *ret_buffer_len,
 		int type, const char *str, int str_len)
 {
 	part_string_t ps;
 	int len;
 
-	if (str_len < 1)
-		return (-1);
-
 	len = 4 + str_len + 1;
 	if (*ret_buffer_len < len)
 		return (-1);
@@ -201,10 +362,11 @@ static int write_part_string (char **ret_buffer, int *ret_buffer_len,
 	ps.value = (char *) (ps.head + 1);
 
 	ps.head->type = htons ((uint16_t) type);
-	ps.head->length = htons ((uint16_t) str_len + 4);
-	memcpy (ps.value, str, str_len);
+	ps.head->length = htons ((uint16_t) str_len + 5);
+	if (str_len > 0)
+		memcpy (ps.value, str, str_len);
 	ps.value[str_len] = '\0';
-	*ret_buffer = (void *) (ps.value + str_len);
+	*ret_buffer = (void *) (ps.value + (str_len + 1));
 
 	return (0);
 } /* int write_part_string */
@@ -214,83 +376,124 @@ static int parse_part_values (void **ret_buffer, int *ret_buffer_len,
 {
 	char *buffer = *ret_buffer;
 	int   buffer_len = *ret_buffer_len;
-	part_values_t *pvalues;
+	part_values_t pv;
 	int   i;
 
+	uint16_t h_length;
+	uint16_t h_type;
+	uint16_t h_num;
+
 	if (buffer_len < (15))
 	{
-		DBG ("packet is too short");
+		DEBUG ("network plugin: packet is too short: buffer_len = %i",
+				buffer_len);
 		return (-1);
 	}
 
-	pvalues = (part_values_t *) malloc (sizeof (part_values_t));
-	if (pvalues == NULL)
-		return (-1);
+	pv.head = (part_header_t *) buffer;
+	h_length = ntohs (pv.head->length);
+	h_type = ntohs (pv.head->type);
+
+	assert (h_type == TYPE_VALUES);
 
-	pvalues->head = (part_header_t *) buffer;
-	assert (pvalues->head->type == htons (TYPE_VALUES));
+	pv.num_values = (uint16_t *) (pv.head + 1);
+	h_num = ntohs (*pv.num_values);
 
-	pvalues->num_values = (uint16_t *) (buffer + 4);
-	if (ntohs (*pvalues->num_values)
-			!= ((ntohs (pvalues->head->length) - 6) / 9))
+	if (h_num != ((h_length - 6) / 9))
 	{
-		DBG ("`length' and `num of values' don't match");
-		free (pvalues);
+		DEBUG ("`length' and `num of values' don't match");
 		return (-1);
 	}
 
-	pvalues->values_types = (uint8_t *) (buffer + 6);
-	pvalues->values = (value_t *) (buffer + 6 + *pvalues->num_values);
-
-	for (i = 0; i < *pvalues->num_values; i++)
-		if (pvalues->values_types[i] == DS_TYPE_COUNTER)
-			pvalues->values[i].counter = ntohll (pvalues->values[i].counter);
+	pv.values_types = (uint8_t *) (pv.num_values + 1);
+	pv.values = (value_t *) (pv.values_types + h_num);
 
-	*ret_buffer     = (void *) buffer;
-	*ret_buffer_len = buffer_len - pvalues->head->length;
-	*ret_num_values = *pvalues->num_values;
-	*ret_values     = pvalues->values;
+	for (i = 0; i < h_num; i++)
+		if (pv.values_types[i] == DS_TYPE_COUNTER)
+			pv.values[i].counter = ntohll (pv.values[i].counter);
 
-	free (pvalues);
+	*ret_buffer     = (void *) (pv.values + h_num);
+	*ret_buffer_len = buffer_len - h_length;
+	*ret_num_values = h_num;
+	*ret_values     = pv.values;
 
 	return (0);
 } /* int parse_part_values */
 
+static int parse_part_number (void **ret_buffer, int *ret_buffer_len,
+		uint64_t *value)
+{
+	part_number_t pn;
+	uint16_t len;
+
+	pn.head = (part_header_t *) *ret_buffer;
+	pn.value = (uint64_t *) (pn.head + 1);
+
+	len = ntohs (pn.head->length);
+	if (len != 12)
+		return (-1);
+	if (len > *ret_buffer_len)
+		return (-1);
+	*value = ntohll (*pn.value);
+
+	*ret_buffer = (void *) (pn.value + 1);
+	*ret_buffer_len -= len;
+
+	return (0);
+} /* int parse_part_number */
+
 static int parse_part_string (void **ret_buffer, int *ret_buffer_len,
 		char *output, int output_len)
 {
 	char *buffer = *ret_buffer;
 	int   buffer_len = *ret_buffer_len;
-	part_string_t part_string;
+	part_string_t ps;
+
+	uint16_t h_length;
+	uint16_t h_type;
 
-	part_string.head = (part_header_t *) buffer;
-	if (buffer_len < part_string.head->length)
+	DEBUG ("network plugin: parse_part_string: ret_buffer = %p;"
+			" ret_buffer_len = %i; output = %p; output_len = %i;",
+			*ret_buffer, *ret_buffer_len,
+			(void *) output, output_len);
+
+	ps.head = (part_header_t *) buffer;
+
+	h_length = ntohs (ps.head->length);
+	h_type = ntohs (ps.head->type);
+
+	DEBUG ("network plugin: parse_part_string: length = %hu; type = %hu;",
+			h_length, h_type);
+
+	if (buffer_len < h_length)
 	{
-		DBG ("packet is too short");
+		DEBUG ("packet is too short");
 		return (-1);
 	}
-	assert ((part_string.head->type == htons (TYPE_HOST))
-			|| (part_string.head->type == htons (TYPE_PLUGIN))
-			|| (part_string.head->type == htons (TYPE_PLUGIN_INSTANCE))
-			|| (part_string.head->type == htons (TYPE_TYPE))
-			|| (part_string.head->type == htons (TYPE_TYPE_INSTANCE)));
-
-	part_string.value = buffer + 4;
-	if (part_string.value[part_string.head->length - 5] != '\0')
+	assert ((h_type == TYPE_HOST)
+			|| (h_type == TYPE_PLUGIN)
+			|| (h_type == TYPE_PLUGIN_INSTANCE)
+			|| (h_type == TYPE_TYPE)
+			|| (h_type == TYPE_TYPE_INSTANCE));
+
+	ps.value = buffer + 4;
+	if (ps.value[h_length - 5] != '\0')
 	{
-		DBG ("String does not end with a nullbyte");
+		DEBUG ("String does not end with a nullbyte");
 		return (-1);
 	}
 
-	if (output_len < (part_string.head->length - 4))
+	if (output_len < (h_length - 4))
 	{
-		DBG ("output buffer is too small");
+		DEBUG ("output buffer is too small");
 		return (-1);
 	}
-	strcpy (output, part_string.value);
+	strcpy (output, ps.value);
+
+	DEBUG ("network plugin: parse_part_string: output = %s", output);
 
-	*ret_buffer = (void *) (buffer + part_string.head->length);
-	*ret_buffer_len = buffer_len - part_string.head->length;
+	*ret_buffer = (void *) (buffer + h_length);
+	*ret_buffer_len = buffer_len - h_length;
 
 	return (0);
 } /* int parse_part_string */
@@ -300,59 +503,102 @@ static int parse_packet (void *buffer, int buffer_len)
 	part_header_t *header;
 	int status;
 
-	value_list_t vl;
+	value_list_t vl = VALUE_LIST_INIT;
 	char type[DATA_MAX_NAME_LEN];
 
+	DEBUG ("network plugin: parse_packet: buffer = %p; buffer_len = %i;",
+			buffer, buffer_len);
+
 	memset (&vl, '\0', sizeof (vl));
 	memset (&type, '\0', sizeof (type));
+	status = 0;
 
-	while (buffer_len > sizeof (part_header_t))
+	while ((status == 0) && (buffer_len > sizeof (part_header_t)))
 	{
 		header = (part_header_t *) buffer;
 
-		if (header->length > buffer_len)
+		if (ntohs (header->length) > buffer_len)
+			break;
+		/* Assure that this loop terminates eventually */
+		if (ntohs (header->length) < 4)
 			break;
 
-		if (header->type == TYPE_VALUES)
+		if (ntohs (header->type) == TYPE_VALUES)
 		{
 			status = parse_part_values (&buffer, &buffer_len,
 					&vl.values, &vl.values_len);
 
-			if ((status == 0)
+			if (status != 0)
+			{
+				DEBUG ("parse_part_values failed.");
+				break;
+			}
+
+			if ((vl.time > 0)
 					&& (strlen (vl.host) > 0)
 					&& (strlen (vl.plugin) > 0)
-					&& (strlen (type) > 0))
+					&& (strlen (type) > 0)
+					&& (cache_check (type, &vl) == 0))
+			{
+				DEBUG ("network plugin: parse_packet:"
+						" dispatching values");
 				plugin_dispatch_values (type, &vl);
+			}
+			else
+			{
+				DEBUG ("network plugin: parse_packet:"
+						" NOT dispatching values");
+			}
+		}
+		else if (ntohs (header->type) == TYPE_TIME)
+		{
+			uint64_t tmp = 0;
+			status = parse_part_number (&buffer, &buffer_len, &tmp);
+			if (status == 0)
+				vl.time = (time_t) tmp;
 		}
-		else if (header->type == TYPE_HOST)
+		else if (ntohs (header->type) == TYPE_INTERVAL)
+		{
+			uint64_t tmp = 0;
+			status = parse_part_number (&buffer, &buffer_len, &tmp);
+			if (status == 0)
+				vl.interval = (int) tmp;
+		}
+		else if (ntohs (header->type) == TYPE_HOST)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.host, sizeof (vl.host));
+			DEBUG ("network plugin: parse_packet: vl.host = %s", vl.host);
 		}
-		else if (header->type == TYPE_PLUGIN)
+		else if (ntohs (header->type) == TYPE_PLUGIN)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.plugin, sizeof (vl.plugin));
+			DEBUG ("network plugin: parse_packet: vl.plugin = %s", vl.plugin);
 		}
-		else if (header->type == TYPE_PLUGIN_INSTANCE)
+		else if (ntohs (header->type) == TYPE_PLUGIN_INSTANCE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.plugin_instance, sizeof (vl.plugin_instance));
+			DEBUG ("network plugin: parse_packet: vl.plugin_instance = %s", vl.plugin_instance);
 		}
-		else if (header->type == TYPE_TYPE)
+		else if (ntohs (header->type) == TYPE_TYPE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					type, sizeof (type));
+			DEBUG ("network plugin: parse_packet: type = %s", type);
 		}
-		else if (header->type == TYPE_TYPE_INSTANCE)
+		else if (ntohs (header->type) == TYPE_TYPE_INSTANCE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.type_instance, sizeof (vl.type_instance));
+			DEBUG ("network plugin: parse_packet: vl.type_instance = %s", vl.type_instance);
 		}
 		else
 		{
-			DBG ("Unknown part type: 0x%0hx", header->type);
-			buffer = ((char *) buffer) + header->length;
+			DEBUG ("network plugin: parse_packet: Unknown part"
+					" type: 0x%0hx", ntohs (header->type));
+			buffer = ((char *) buffer) + ntohs (header->length);
 		}
 	} /* while (buffer_len > sizeof (part_header_t)) */
 
@@ -385,7 +631,7 @@ static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
 	if ((network_config_ttl < 1) || (network_config_ttl > 255))
 		return (-1);
 
-	DBG ("ttl = %i", network_config_ttl);
+	DEBUG ("ttl = %i", network_config_ttl);
 
 	if (ai->ai_family == AF_INET)
 	{
@@ -401,7 +647,9 @@ static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
 					&network_config_ttl,
 					sizeof (network_config_ttl)) == -1)
 		{
-			syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+			char errbuf[1024];
+			ERROR ("setsockopt: %s",
+					sstrerror (errno, errbuf, sizeof (errbuf)));
 			return (-1);
 		}
 	}
@@ -420,7 +668,10 @@ static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
 					&network_config_ttl,
 					sizeof (network_config_ttl)) == -1)
 		{
-			syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+			char errbuf[1024];
+			ERROR ("setsockopt: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
 			return (-1);
 		}
 	}
@@ -430,13 +681,25 @@ static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
 
 static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
 {
-	int loop = 1;
+	int loop = 0;
+	int yes  = 1;
+
+	/* allow multiple sockets to use the same PORT number */
+	if (setsockopt(se->fd, SOL_SOCKET, SO_REUSEADDR,
+				&yes, sizeof(yes)) == -1) {
+                char errbuf[1024];
+                ERROR ("setsockopt: %s", 
+                                sstrerror (errno, errbuf, sizeof (errbuf)));
+		return (-1);
+	}
 
-	DBG ("fd = %i; calling `bind'", se->fd);
+	DEBUG ("fd = %i; calling `bind'", se->fd);
 
 	if (bind (se->fd, ai->ai_addr, ai->ai_addrlen) == -1)
 	{
-		syslog (LOG_ERR, "bind: %s", strerror (errno));
+		char errbuf[1024];
+		ERROR ("bind: %s",
+				sstrerror (errno, errbuf, sizeof (errbuf)));
 		return (-1);
 	}
 
@@ -447,7 +710,7 @@ static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
 		{
 			struct ip_mreq mreq;
 
-			DBG ("fd = %i; IPv4 multicast address found", se->fd);
+			DEBUG ("fd = %i; IPv4 multicast address found", se->fd);
 
 			mreq.imr_multiaddr.s_addr = addr->sin_addr.s_addr;
 			mreq.imr_interface.s_addr = htonl (INADDR_ANY);
@@ -455,14 +718,20 @@ static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
 			if (setsockopt (se->fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 						&loop, sizeof (loop)) == -1)
 			{
-				syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+				char errbuf[1024];
+				ERROR ("setsockopt: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				return (-1);
 			}
 
 			if (setsockopt (se->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 						&mreq, sizeof (mreq)) == -1)
 			{
-				syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+				char errbuf[1024];
+				ERROR ("setsockopt: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				return (-1);
 			}
 		}
@@ -475,7 +744,7 @@ static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
 		{
 			struct ipv6_mreq mreq;
 
-			DBG ("fd = %i; IPv6 multicast address found", se->fd);
+			DEBUG ("fd = %i; IPv6 multicast address found", se->fd);
 
 			memcpy (&mreq.ipv6mr_multiaddr,
 					&addr->sin6_addr,
@@ -495,14 +764,20 @@ static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
 			if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
 						&loop, sizeof (loop)) == -1)
 			{
-				syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+				char errbuf[1024];
+				ERROR ("setsockopt: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				return (-1);
 			}
 
 			if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP,
 						&mreq, sizeof (mreq)) == -1)
 			{
-				syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
+				char errbuf[1024];
+				ERROR ("setsockopt: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				return (-1);
 			}
 		}
@@ -522,7 +797,7 @@ static sockent_t *network_create_socket (const char *node,
 	sockent_t *se_head = NULL;
 	sockent_t *se_tail = NULL;
 
-	DBG ("node = %s, service = %s", node, service);
+	DEBUG ("node = %s, service = %s", node, service);
 
 	memset (&ai_hints, '\0', sizeof (ai_hints));
 	ai_hints.ai_flags    = 0;
@@ -539,11 +814,12 @@ static sockent_t *network_create_socket (const char *node,
 	ai_return = getaddrinfo (node, service, &ai_hints, &ai_list);
 	if (ai_return != 0)
 	{
-		syslog (LOG_ERR, "getaddrinfo (%s, %s): %s",
+		char errbuf[1024];
+		ERROR ("getaddrinfo (%s, %s): %s",
 				(node == NULL) ? "(null)" : node,
 				(service == NULL) ? "(null)" : service,
 				(ai_return == EAI_SYSTEM)
-				? strerror (errno)
+				? sstrerror (errno, errbuf, sizeof (errbuf))
 				: gai_strerror (ai_return));
 		return (NULL);
 	}
@@ -554,13 +830,19 @@ static sockent_t *network_create_socket (const char *node,
 
 		if ((se = (sockent_t *) malloc (sizeof (sockent_t))) == NULL)
 		{
-			syslog (LOG_EMERG, "malloc: %s", strerror (errno));
+			char errbuf[1024];
+			ERROR ("malloc: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
 			continue;
 		}
 
 		if ((se->addr = (struct sockaddr_storage *) malloc (sizeof (struct sockaddr_storage))) == NULL)
 		{
-			syslog (LOG_EMERG, "malloc: %s", strerror (errno));
+			char errbuf[1024];
+			ERROR ("malloc: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
 			free (se);
 			continue;
 		}
@@ -577,7 +859,10 @@ static sockent_t *network_create_socket (const char *node,
 
 		if (se->fd == -1)
 		{
-			syslog (LOG_ERR, "socket: %s", strerror (errno));
+			char errbuf[1024];
+			ERROR ("socket: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
 			free (se->addr);
 			free (se);
 			continue;
@@ -587,6 +872,7 @@ static sockent_t *network_create_socket (const char *node,
 		{
 			if (network_bind_socket (se, ai_ptr) != 0)
 			{
+				close (se->fd);
 				free (se->addr);
 				free (se);
 				continue;
@@ -726,7 +1012,7 @@ int network_receive (void)
 
 	if (listen_sockets_num == 0)
 	{
-		syslog (LOG_ERR, "network: Failed to open a listening socket.");
+		ERROR ("network: Failed to open a listening socket.");
 		return (-1);
 	}
 
@@ -736,10 +1022,11 @@ int network_receive (void)
 
 		if (status <= 0)
 		{
+			char errbuf[1024];
 			if (errno == EINTR)
 				continue;
-			syslog (LOG_ERR, "poll failed: %s",
-					strerror (errno));
+			ERROR ("poll failed: %s",
+					sstrerror (errno, errbuf, sizeof (errbuf)));
 			return (-1);
 		}
 
@@ -754,7 +1041,10 @@ int network_receive (void)
 					0 /* no flags */);
 			if (buffer_len < 0)
 			{
-				syslog (LOG_ERR, "recv failed: %s", strerror (errno));
+				char errbuf[1024];
+				ERROR ("recv failed: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				return (-1);
 			}
 
@@ -767,131 +1057,174 @@ int network_receive (void)
 
 static void *receive_thread (void *arg)
 {
-	return ((void *) network_receive ());
+	return (network_receive () ? (void *) 1 : (void *) 0);
 } /* void *receive_thread */
 
-#if 0
-int network_send (char *type, char *inst, char *value)
+static void network_send_buffer (const char *buffer, int buffer_len)
 {
-	char buf[BUFF_SIZE];
-	int buflen;
-
 	sockent_t *se;
-
-	int ret;
 	int status;
 
-	DBG ("type = %s, inst = %s, value = %s", type, inst, value);
-
-	assert (operating_mode == MODE_CLIENT);
-
-	buflen = snprintf (buf, BUFF_SIZE, "%s %s %s", type, inst, value);
-	if ((buflen >= BUFF_SIZE) || (buflen < 1))
-	{
-		syslog (LOG_WARNING, "network_send: snprintf failed..");
-		return (-1);
-	}
-	buf[buflen] = '\0';
-	buflen++;
-
-	if (socklist_head == NULL)
-		network_create_default_socket (0 /* listen == false */);
+	DEBUG ("network plugin: network_send_buffer: buffer_len = %i", buffer_len);
 
-	ret = 0;
-	for (se = socklist_head; se != NULL; se = se->next)
+	for (se = sending_sockets; se != NULL; se = se->next)
 	{
-		while (1)
+		while (42)
 		{
-			status = sendto (se->fd, buf, buflen, 0,
+			status = sendto (se->fd, buffer, buffer_len, 0 /* no flags */,
 					(struct sockaddr *) se->addr, se->addrlen);
-
-			if (status == -1)
+			if (status < 0)
 			{
+				char errbuf[1024];
 				if (errno == EINTR)
-				{
-					DBG ("sendto was interrupted");
 					continue;
-				}
-				else
-				{
-					syslog (LOG_ERR, "sendto: %s", strerror (errno));
-					ret = -1;
-					break;
-				}
+				ERROR ("network plugin: sendto failed: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
+				break;
 			}
-			else if (ret >= 0)
-				ret++;
+
 			break;
-		}
-	}
+		} /* while (42) */
+	} /* for (sending_sockets) */
+} /* void network_send_buffer */
 
-	if (ret == 0)
-		syslog (LOG_WARNING, "Message wasn't sent to anybody..");
+static int add_to_buffer (char *buffer, int buffer_size,
+		value_list_t *vl_def, char *type_def,
+		const data_set_t *ds, const value_list_t *vl)
+{
+	char *buffer_orig = buffer;
 
-	return (ret);
-} /* int network_send */
-#endif
+	if (strcmp (vl_def->host, vl->host) != 0)
+	{
+		if (write_part_string (&buffer, &buffer_size, TYPE_HOST,
+					vl->host, strlen (vl->host)) != 0)
+			return (-1);
+		strcpy (vl_def->host, vl->host);
+	}
 
-static int network_write (const data_set_t *ds, const value_list_t *vl)
-{
-	char  buf[BUFF_SIZE];
-	char *buf_ptr;
-	int   buf_len;
+	if (vl_def->time != vl->time)
+	{
+		if (write_part_number (&buffer, &buffer_size, TYPE_TIME,
+					(uint64_t) vl->time))
+			return (-1);
+		vl_def->time = vl->time;
+	}
 
-	sockent_t *se;
+	if (vl_def->interval != vl->interval)
+	{
+		if (write_part_number (&buffer, &buffer_size, TYPE_INTERVAL,
+					(uint64_t) vl->interval))
+			return (-1);
+		vl_def->interval = vl->interval;
+	}
 
-	DBG ("host = %s; plugin = %s; plugin_instance = %s; type = %s; type_instance = %s;",
-			vl->host, vl->plugin, vl->plugin_instance, ds->type, vl->type_instance);
+	if (strcmp (vl_def->plugin, vl->plugin) != 0)
+	{
+		if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN,
+					vl->plugin, strlen (vl->plugin)) != 0)
+			return (-1);
+		strcpy (vl_def->plugin, vl->plugin);
+	}
 
-	buf_len = sizeof (buf);
-	buf_ptr = buf;
-	if (write_part_string (&buf_ptr, &buf_len, TYPE_HOST,
-				vl->host, strlen (vl->host)) != 0)
-		return (-1);
-	if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN,
-				vl->plugin, strlen (vl->plugin)) != 0)
-		return (-1);
-	if (strlen (vl->plugin_instance) > 0)
-		if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN_INSTANCE,
+	if (strcmp (vl_def->plugin_instance, vl->plugin_instance) != 0)
+	{
+		if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN_INSTANCE,
 					vl->plugin_instance,
 					strlen (vl->plugin_instance)) != 0)
 			return (-1);
-	if (write_part_string (&buf_ptr, &buf_len, TYPE_TYPE,
-				ds->type, strlen (ds->type)) != 0)
-		return (-1);
-	if (strlen (vl->type_instance) > 0)
-		if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN_INSTANCE,
+		strcpy (vl_def->plugin_instance, vl->plugin_instance);
+	}
+
+	if (strcmp (type_def, ds->type) != 0)
+	{
+		if (write_part_string (&buffer, &buffer_size, TYPE_TYPE,
+					ds->type, strlen (ds->type)) != 0)
+			return (-1);
+		strcpy (type_def, ds->type);
+	}
+
+	if (strcmp (vl_def->type_instance, vl->type_instance) != 0)
+	{
+		if (write_part_string (&buffer, &buffer_size, TYPE_TYPE_INSTANCE,
 					vl->type_instance,
 					strlen (vl->type_instance)) != 0)
 			return (-1);
+		strcpy (vl_def->type_instance, vl->type_instance);
+	}
 	
-	write_part_values (&buf_ptr, &buf_len, ds, vl);
+	if (write_part_values (&buffer, &buffer_size, ds, vl) != 0)
+		return (-1);
 
-	buf_len = sizeof (buf) - buf_len;
+	return (buffer - buffer_orig);
+} /* int add_to_buffer */
 
-	for (se = sending_sockets; se != NULL; se = se->next)
+static void flush_buffer (void)
+{
+	DEBUG ("network plugin: flush_buffer: send_buffer_fill = %i",
+			send_buffer_fill);
+
+	network_send_buffer (send_buffer, send_buffer_fill);
+	send_buffer_ptr  = send_buffer;
+	send_buffer_fill = 0;
+	memset (&send_buffer_vl, '\0', sizeof (send_buffer_vl));
+	memset (send_buffer_type, '\0', sizeof (send_buffer_type));
+}
+
+static int network_write (const data_set_t *ds, const value_list_t *vl)
+{
+	int status;
+
+	/* If the value is already in the cache, we have received it via the
+	 * network. We write it again if forwarding is activated. It's then in
+	 * the cache and should we receive it again we will ignore it. */
+	status = cache_check (ds->type, vl);
+	if ((network_config_forward == 0)
+			&& (status != 0))
+		return (0);
+
+	pthread_mutex_lock (&send_buffer_lock);
+
+	status = add_to_buffer (send_buffer_ptr,
+			sizeof (send_buffer) - send_buffer_fill,
+			&send_buffer_vl, send_buffer_type,
+			ds, vl);
+	if (status >= 0)
 	{
-		int status;
+		/* status == bytes added to the buffer */
+		send_buffer_fill += status;
+		send_buffer_ptr  += status;
+	}
+	else
+	{
+		flush_buffer ();
 
-		while (42)
+		status = add_to_buffer (send_buffer_ptr,
+				sizeof (send_buffer) - send_buffer_fill,
+				&send_buffer_vl, send_buffer_type,
+				ds, vl);
+
+		if (status >= 0)
 		{
-			status = sendto (se->fd, buf, buf_len, 0 /* no flags */,
-					(struct sockaddr *) se->addr, se->addrlen);
-			if (status < 0)
-			{
-				if (errno == EINTR)
-					continue;
-				syslog (LOG_ERR, "network: sendto failed: %s",
-						strerror (errno));
-				break;
-			}
+			send_buffer_fill += status;
+			send_buffer_ptr  += status;
+		}
+	}
 
-			break;
-		} /* while (42) */
-	} /* for (sending_sockets) */
+	if (status < 0)
+	{
+		ERROR ("network plugin: Unable to append to the "
+				"buffer for some weird reason");
+	}
+	else if ((sizeof (send_buffer) - send_buffer_fill) < 15)
+	{
+		flush_buffer ();
+	}
 
-	return 0;
-}
+	pthread_mutex_unlock (&send_buffer_lock);
+
+	return ((status < 0) ? -1 : 0);
+} /* int network_write */
 
 static int network_config (const char *key, const char *val)
 {
@@ -914,7 +1247,11 @@ static int network_config (const char *key, const char *val)
 				&& (fields_num != 2))
 			return (1);
 		else if (fields_num == 2)
+		{
+			if ((service = strchr (fields[1], '.')) != NULL)
+				*service = '\0';
 			service = fields[1];
+		}
 		node = fields[0];
 
 		if (strcasecmp ("Listen", key) == 0)
@@ -930,31 +1267,79 @@ static int network_config (const char *key, const char *val)
 		else
 			return (1);
 	}
+	else if (strcasecmp ("Forward", key) == 0)
+	{
+		if ((strcasecmp ("true", val) == 0)
+				|| (strcasecmp ("yes", val) == 0)
+				|| (strcasecmp ("on", val) == 0))
+			network_config_forward = 1;
+		else
+			network_config_forward = 0;
+	}
+	else if (strcasecmp ("CacheFlush", key) == 0)
+	{
+		int tmp = atoi (val);
+		if (tmp > 0)
+			cache_flush_interval = tmp;
+		else return (1);
+	}
 	else
 	{
 		return (-1);
 	}
 	return (0);
-}
+} /* int network_config */
 
 static int network_shutdown (void)
 {
-	DBG ("Shutting down.");
-
 	listen_loop++;
 
-	pthread_kill (listen_thread, SIGTERM);
-	pthread_join (listen_thread, NULL /* no return value */);
+	if (listen_thread != (pthread_t) 0)
+	{
+		pthread_kill (listen_thread, SIGTERM);
+		pthread_join (listen_thread, NULL /* no return value */);
+		listen_thread = (pthread_t) 0;
+	}
 
-	listen_thread = 0;
+	if (send_buffer_fill > 0)
+		flush_buffer ();
+
+	if (cache_tree != NULL)
+	{
+		void *key;
+		void *value;
+
+		while (avl_pick (cache_tree, &key, &value) == 0)
+		{
+			sfree (key);
+			sfree (value);
+		}
+		avl_destroy (cache_tree);
+		cache_tree = NULL;
+	}
+
+	/* TODO: Close `sending_sockets' */
+
+	plugin_unregister_config ("network");
+	plugin_unregister_init ("network");
+	plugin_unregister_write ("network");
+	plugin_unregister_shutdown ("network");
 
 	return (0);
-}
+} /* int network_shutdown */
 
 static int network_init (void)
 {
 	plugin_register_shutdown ("network", network_shutdown);
 
+	send_buffer_ptr  = send_buffer;
+	send_buffer_fill = 0;
+	memset (&send_buffer_vl, '\0', sizeof (send_buffer_vl));
+	memset (send_buffer_type, '\0', sizeof (send_buffer_type));
+
+	cache_tree = avl_create ((int (*) (const void *, const void *)) strcmp);
+	cache_flush_last = time (NULL);
+
 	/* setup socket(s) and so on */
 	if (sending_sockets != NULL)
 		plugin_register_write ("network", network_write);
@@ -967,8 +1352,12 @@ static int network_init (void)
 				receive_thread, NULL /* no argument */);
 
 		if (status != 0)
-			syslog (LOG_ERR, "network: pthread_create failed: %s",
-					strerror (errno));
+		{
+			char errbuf[1024];
+			ERROR ("network: pthread_create failed: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
+		}
 	}
 	return (0);
 } /* int network_init */
@@ -978,4 +1367,4 @@ void module_register (void)
 	plugin_register_config ("network", network_config,
 			config_keys, config_keys_num);
 	plugin_register_init   ("network", network_init);
-}
+} /* void module_register */