X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fnetwork.c;h=c347552e904a981b0588028093ed759b10847d61;hb=c88e459eb3823b766fc3a9ed37f25bc1f630146c;hp=cf2a01799cbb1723c710357be176810aac053fb6;hpb=6360474f4aa35dd1a587b6148ff88a23e6155132;p=collectd.git

diff --git a/src/network.c b/src/network.c
index cf2a0179..c347552e 100644
--- a/src/network.c
+++ b/src/network.c
@@ -23,7 +23,7 @@
 #include "plugin.h"
 #include "common.h"
 #include "configfile.h"
-#include "utils_debug.h"
+#include "utils_avltree.h"
 
 #include "network.h"
 
@@ -141,14 +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;
 
@@ -160,12 +162,132 @@ 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_INIT;
+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 c_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;
+	c_avl_iterator_t *iter;
+
+	time_t curtime = time (NULL);
+
+	iter = c_avl_get_iterator (cache_tree);
+	while (c_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);
+			c_avl_iterator_destroy (iter);
+			ERROR ("network plugin: cache_flush: realloc"
+					" failed.");
+			return (-1);
+		}
+		keys = tmp;
+		keys[keys_num] = key;
+		keys_num++;
+	} /* while (c_avl_iterator_next) */
+	c_avl_iterator_destroy (iter);
+
+	for (i = 0; i < keys_num; i++)
+	{
+		if (c_avl_remove (cache_tree, keys[i], (void *) &key,
+					(void *) &value) != 0)
+		{
+			WARNING ("network plugin: cache_flush: c_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 (c_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;
+			c_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)
 {
@@ -263,7 +385,8 @@ static int parse_part_values (void **ret_buffer, int *ret_buffer_len,
 
 	if (buffer_len < (15))
 	{
-		DBG ("packet is too short: buffer_len = %i", buffer_len);
+		DEBUG ("network plugin: packet is too short: buffer_len = %i",
+				buffer_len);
 		return (-1);
 	}
 
@@ -278,7 +401,7 @@ static int parse_part_values (void **ret_buffer, int *ret_buffer_len,
 
 	if (h_num != ((h_length - 6) / 9))
 	{
-		DBG ("`length' and `num of values' don't match");
+		DEBUG ("`length' and `num of values' don't match");
 		return (-1);
 	}
 
@@ -329,7 +452,8 @@ static int parse_part_string (void **ret_buffer, int *ret_buffer_len,
 	uint16_t h_length;
 	uint16_t h_type;
 
-	DBG ("ret_buffer = %p; ret_buffer_len = %i; output = %p; output_len = %i;",
+	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);
 
@@ -338,11 +462,12 @@ static int parse_part_string (void **ret_buffer, int *ret_buffer_len,
 	h_length = ntohs (ps.head->length);
 	h_type = ntohs (ps.head->type);
 
-	DBG ("length = %hu; type = %hu;", h_length, h_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 ((h_type == TYPE_HOST)
@@ -354,18 +479,18 @@ static int parse_part_string (void **ret_buffer, int *ret_buffer_len,
 	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 < (h_length - 4))
 	{
-		DBG ("output buffer is too small");
+		DEBUG ("output buffer is too small");
 		return (-1);
 	}
 	strcpy (output, ps.value);
 
-	DBG ("output = %s", output);
+	DEBUG ("network plugin: parse_part_string: output = %s", output);
 
 	*ret_buffer = (void *) (buffer + h_length);
 	*ret_buffer_len = buffer_len - h_length;
@@ -381,7 +506,8 @@ static int parse_packet (void *buffer, int buffer_len)
 	value_list_t vl = VALUE_LIST_INIT;
 	char type[DATA_MAX_NAME_LEN];
 
-	DBG ("buffer = %p; buffer_len = %i;", buffer, buffer_len);
+	DEBUG ("network plugin: parse_packet: buffer = %p; buffer_len = %i;",
+			buffer, buffer_len);
 
 	memset (&vl, '\0', sizeof (vl));
 	memset (&type, '\0', sizeof (type));
@@ -393,67 +519,86 @@ static int parse_packet (void *buffer, int buffer_len)
 
 		if (ntohs (header->length) > buffer_len)
 			break;
+		/* Assure that this loop terminates eventually */
+		if (ntohs (header->length) < 4)
+			break;
 
-		if (header->type == htons (TYPE_VALUES))
+		if (ntohs (header->type) == TYPE_VALUES)
 		{
 			status = parse_part_values (&buffer, &buffer_len,
 					&vl.values, &vl.values_len);
 
 			if (status != 0)
 			{
-				DBG ("parse_part_values failed.");
+				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))
 			{
-				DBG ("dispatching values");
+				DEBUG ("network plugin: parse_packet:"
+						" dispatching values");
 				plugin_dispatch_values (type, &vl);
 			}
 			else
 			{
-				DBG ("NOT dispatching values");
+				DEBUG ("network plugin: parse_packet:"
+						" NOT dispatching values");
 			}
 		}
-		else if (header->type == ntohs (TYPE_TIME))
+		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 == ntohs (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 == ntohs (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 == ntohs (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 == ntohs (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 == ntohs (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)) */
 
@@ -486,7 +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)
 	{
@@ -502,7 +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);
 		}
 	}
@@ -521,7 +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);
 		}
 	}
@@ -531,13 +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);
 	}
 
@@ -548,7 +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);
@@ -556,14 +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);
 			}
 		}
@@ -576,7 +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,
@@ -596,14 +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);
 			}
 		}
@@ -623,7 +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;
@@ -640,11 +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);
 	}
@@ -655,13 +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;
 		}
@@ -678,7 +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;
@@ -815,7 +999,7 @@ static int network_add_sending_socket (const char *node, const char *service)
 	return (0);
 } /* int network_get_listen_socket */
 
-int network_receive (void)
+static int network_receive (void)
 {
 	char buffer[BUFF_SIZE];
 	int  buffer_len;
@@ -828,7 +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);
 	}
 
@@ -838,10 +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);
 		}
 
@@ -856,7 +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);
 			}
 
@@ -877,7 +1065,7 @@ static void network_send_buffer (const char *buffer, int buffer_len)
 	sockent_t *se;
 	int status;
 
-	DBG ("buffer_len = %i", buffer_len);
+	DEBUG ("network plugin: network_send_buffer: buffer_len = %i", buffer_len);
 
 	for (se = sending_sockets; se != NULL; se = se->next)
 	{
@@ -887,10 +1075,12 @@ static void network_send_buffer (const char *buffer, int buffer_len)
 					(struct sockaddr *) se->addr, se->addrlen);
 			if (status < 0)
 			{
+				char errbuf[1024];
 				if (errno == EINTR)
 					continue;
-				syslog (LOG_ERR, "network plugin: sendto failed: %s",
-						strerror (errno));
+				ERROR ("network plugin: sendto failed: %s",
+						sstrerror (errno, errbuf,
+							sizeof (errbuf)));
 				break;
 			}
 
@@ -903,13 +1093,14 @@ 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;
+
 	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);
-		DBG ("host = %s", vl->host);
 	}
 
 	if (vl_def->time != vl->time)
@@ -918,7 +1109,14 @@ static int add_to_buffer (char *buffer, int buffer_size,
 					(uint64_t) vl->time))
 			return (-1);
 		vl_def->time = vl->time;
-		DBG ("time = %u", (unsigned int) vl->time);
+	}
+
+	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;
 	}
 
 	if (strcmp (vl_def->plugin, vl->plugin) != 0)
@@ -927,7 +1125,6 @@ static int add_to_buffer (char *buffer, int buffer_size,
 					vl->plugin, strlen (vl->plugin)) != 0)
 			return (-1);
 		strcpy (vl_def->plugin, vl->plugin);
-		DBG ("plugin = %s", vl->plugin);
 	}
 
 	if (strcmp (vl_def->plugin_instance, vl->plugin_instance) != 0)
@@ -937,7 +1134,6 @@ static int add_to_buffer (char *buffer, int buffer_size,
 					strlen (vl->plugin_instance)) != 0)
 			return (-1);
 		strcpy (vl_def->plugin_instance, vl->plugin_instance);
-		DBG ("plugin_instance = %s", vl->plugin_instance);
 	}
 
 	if (strcmp (type_def, ds->type) != 0)
@@ -946,27 +1142,28 @@ static int add_to_buffer (char *buffer, int buffer_size,
 					ds->type, strlen (ds->type)) != 0)
 			return (-1);
 		strcpy (type_def, ds->type);
-		DBG ("type = %s", ds->type);
 	}
 
 	if (strcmp (vl_def->type_instance, vl->type_instance) != 0)
 	{
-		if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN_INSTANCE,
+		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);
-		DBG ("type_instance = %s", vl->type_instance);
 	}
 	
 	if (write_part_values (&buffer, &buffer_size, ds, vl) != 0)
 		return (-1);
 
-	return (buffer_size);
+	return (buffer - buffer_orig);
 } /* int add_to_buffer */
 
 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;
@@ -977,13 +1174,24 @@ static void flush_buffer (void)
 static int network_write (const data_set_t *ds, const value_list_t *vl)
 {
 	int status;
-	/* TODO: lock buffer */
+
+	/* 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)
 	{
+		/* status == bytes added to the buffer */
 		send_buffer_fill += status;
 		send_buffer_ptr  += status;
 	}
@@ -1005,14 +1213,15 @@ static int network_write (const data_set_t *ds, const value_list_t *vl)
 
 	if (status < 0)
 	{
-		syslog (LOG_ERR, "network plugin: Unable to append to the "
+		ERROR ("network plugin: Unable to append to the "
 				"buffer for some weird reason");
 	}
 	else if ((sizeof (send_buffer) - send_buffer_fill) < 15)
 	{
 		flush_buffer ();
 	}
-	/* TODO: unlock buffer */
+
+	pthread_mutex_unlock (&send_buffer_lock);
 
 	return ((status < 0) ? -1 : 0);
 } /* int network_write */
@@ -1038,7 +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)
@@ -1054,26 +1267,66 @@ 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;
+	}
+
+	if (send_buffer_fill > 0)
+		flush_buffer ();
 
-	listen_thread = 0;
+	if (cache_tree != NULL)
+	{
+		void *key;
+		void *value;
+
+		while (c_avl_pick (cache_tree, &key, &value) == 0)
+		{
+			sfree (key);
+			sfree (value);
+		}
+		c_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)
 {
@@ -1084,6 +1337,9 @@ static int network_init (void)
 	memset (&send_buffer_vl, '\0', sizeof (send_buffer_vl));
 	memset (send_buffer_type, '\0', sizeof (send_buffer_type));
 
+	cache_tree = c_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);
@@ -1096,8 +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 */
@@ -1107,4 +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 */