X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fnetwork.c;h=34a16690953048a589f0f5c0f82ee45e8207c9dd;hb=1d3482c65a00342de681e777c74108734ece0eab;hp=cf2a01799cbb1723c710357be176810aac053fb6;hpb=5661326c8102fa9035b870316e9f152f43aca31c;p=collectd.git

diff --git a/src/network.c b/src/network.c
index cf2a0179..34a16690 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"
 
@@ -136,70 +136,253 @@ struct part_values_s
 };
 typedef struct part_values_s part_values_t;
 
+struct receive_list_entry_s
+{
+  char data[BUFF_SIZE];
+  int  data_len;
+  struct receive_list_entry_s *next;
+};
+typedef struct receive_list_entry_s receive_list_entry_t;
+
 /*
  * Private variables
  */
 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;
 
+static receive_list_entry_t *receive_list_head = NULL;
+static receive_list_entry_t *receive_list_tail = NULL;
+static pthread_mutex_t       receive_list_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t        receive_list_cond = PTHREAD_COND_INITIALIZER;
+
 static struct pollfd *listen_sockets = NULL;
 static int listen_sockets_num = 0;
-static pthread_t listen_thread = 0;
+
 static int listen_loop = 0;
+static pthread_t receive_thread_id = 0;
+static pthread_t dispatch_thread_id = 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)
 {
-	part_values_t pv;
+	char *packet_ptr;
+	int packet_len;
+	int num_values;
+
+	part_header_t pkg_ph;
+	uint16_t      pkg_num_values;
+	uint8_t      *pkg_values_types;
+	value_t      *pkg_values;
+
+	int offset;
 	int i;
 
-	i = 6 + (9 * vl->values_len);
-	if (*ret_buffer_len < i)
+	num_values = vl->values_len;
+	packet_len = sizeof (part_header_t) + sizeof (uint16_t)
+		+ (num_values * sizeof (uint8_t))
+		+ (num_values * sizeof (value_t));
+
+	if (*ret_buffer_len < packet_len)
 		return (-1);
-	*ret_buffer_len -= i;
 
-	pv.head = (part_header_t *) *ret_buffer;
-	pv.num_values = (uint16_t *) (pv.head + 1);
-	pv.values_types = (uint8_t *) (pv.num_values + 1);
-	pv.values = (value_t *) (pv.values_types + vl->values_len);
-	*ret_buffer = (void *) (pv.values + vl->values_len);
+	pkg_values_types = (uint8_t *) malloc (num_values * sizeof (uint8_t));
+	if (pkg_values_types == NULL)
+	{
+		ERROR ("network plugin: write_part_values: malloc failed.");
+		return (-1);
+	}
 
-	pv.head->type = htons (TYPE_VALUES);
-	pv.head->length = htons (6 + (9 * vl->values_len));
-	*pv.num_values = htons ((uint16_t) vl->values_len);
-	
-	for (i = 0; i < vl->values_len; i++)
+	pkg_values = (value_t *) malloc (num_values * sizeof (value_t));
+	if (pkg_values == NULL)
+	{
+		free (pkg_values_types);
+		ERROR ("network plugin: write_part_values: malloc failed.");
+		return (-1);
+	}
+
+	pkg_ph.type = htons (TYPE_VALUES);
+	pkg_ph.length = htons (packet_len);
+
+	pkg_num_values = htons ((uint16_t) vl->values_len);
+
+	for (i = 0; i < num_values; i++)
 	{
 		if (ds->ds[i].type == DS_TYPE_COUNTER)
 		{
-			pv.values_types[i] = DS_TYPE_COUNTER;
-			pv.values[i].counter = htonll (vl->values[i].counter);
+			pkg_values_types[i] = DS_TYPE_COUNTER;
+			pkg_values[i].counter = htonll (vl->values[i].counter);
 		}
 		else
 		{
-			pv.values_types[i] = DS_TYPE_GAUGE;
-			pv.values[i].gauge = vl->values[i].gauge;
+			pkg_values_types[i] = DS_TYPE_GAUGE;
+			pkg_values[i].gauge = htond (vl->values[i].gauge);
 		}
-	} /* for (values) */
+	}
+
+	/*
+	 * Use `memcpy' to write everything to the buffer, because the pointer
+	 * may be unaligned and some architectures, such as SPARC, can't handle
+	 * that.
+	 */
+	packet_ptr = *ret_buffer;
+	offset = 0;
+	memcpy (packet_ptr + offset, &pkg_ph, sizeof (pkg_ph));
+	offset += sizeof (pkg_ph);
+	memcpy (packet_ptr + offset, &pkg_num_values, sizeof (pkg_num_values));
+	offset += sizeof (pkg_num_values);
+	memcpy (packet_ptr + offset, pkg_values_types, num_values * sizeof (uint8_t));
+	offset += num_values * sizeof (uint8_t);
+	memcpy (packet_ptr + offset, pkg_values, num_values * sizeof (value_t));
+	offset += num_values * sizeof (value_t);
+
+	assert (offset == packet_len);
+
+	*ret_buffer = packet_ptr + packet_len;
+	*ret_buffer_len -= packet_len;
+
+	free (pkg_values_types);
+	free (pkg_values);
 
 	return (0);
 } /* int write_part_values */
@@ -207,20 +390,34 @@ static int write_part_values (char **ret_buffer, int *ret_buffer_len,
 static int write_part_number (char **ret_buffer, int *ret_buffer_len,
 		int type, uint64_t value)
 {
-	part_number_t pn;
+	char *packet_ptr;
+	int packet_len;
 
-	if (*ret_buffer_len < 12)
+	part_header_t pkg_head;
+	uint64_t pkg_value;
+	
+	int offset;
+
+	packet_len = sizeof (pkg_head) + sizeof (pkg_value);
+
+	if (*ret_buffer_len < packet_len)
 		return (-1);
 
-	pn.head = (part_header_t *) *ret_buffer;
-	pn.value = (uint64_t *) (pn.head + 1);
+	pkg_head.type = htons (type);
+	pkg_head.length = htons (packet_len);
+	pkg_value = htonll (value);
 
-	pn.head->type = htons (type);
-	pn.head->length = htons (12);
-	*pn.value = htonll (value);
+	packet_ptr = *ret_buffer;
+	offset = 0;
+	memcpy (packet_ptr + offset, &pkg_head, sizeof (pkg_head));
+	offset += sizeof (pkg_head);
+	memcpy (packet_ptr + offset, &pkg_value, sizeof (pkg_value));
+	offset += sizeof (pkg_value);
 
-	*ret_buffer = (char *) (pn.value + 1);
-	*ret_buffer_len -= 12;
+	assert (offset == packet_len);
+
+	*ret_buffer = packet_ptr + packet_len;
+	*ret_buffer_len -= packet_len;
 
 	return (0);
 } /* int write_part_number */
@@ -228,23 +425,36 @@ static int write_part_number (char **ret_buffer, int *ret_buffer_len,
 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;
+	char *buffer;
+	int buffer_len;
+
+	uint16_t pkg_type;
+	uint16_t pkg_length;
+
+	int offset;
 
-	len = 4 + str_len + 1;
-	if (*ret_buffer_len < len)
+	buffer_len = 2 * sizeof (uint16_t) + str_len + 1;
+	if (*ret_buffer_len < buffer_len)
 		return (-1);
-	*ret_buffer_len -= len;
 
-	ps.head = (part_header_t *) *ret_buffer;
-	ps.value = (char *) (ps.head + 1);
+	pkg_type = htons (type);
+	pkg_length = htons (buffer_len);
 
-	ps.head->type = htons ((uint16_t) type);
-	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 + 1));
+	buffer = *ret_buffer;
+	offset = 0;
+	memcpy (buffer + offset, (void *) &pkg_type, sizeof (pkg_type));
+	offset += sizeof (pkg_type);
+	memcpy (buffer + offset, (void *) &pkg_length, sizeof (pkg_length));
+	offset += sizeof (pkg_length);
+	memcpy (buffer + offset, str, str_len);
+	offset += str_len;
+	memset (buffer + offset, '\0', 1);
+	offset += 1;
+
+	assert (offset == buffer_len);
+
+	*ret_buffer = buffer + buffer_len;
+	*ret_buffer_len -= buffer_len;
 
 	return (0);
 } /* int write_part_string */
@@ -254,45 +464,88 @@ 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 pv;
+
+	uint16_t tmp16;
+	size_t exp_size;
 	int   i;
 
-	uint16_t h_length;
-	uint16_t h_type;
-	uint16_t h_num;
+	uint16_t pkg_length;
+	uint16_t pkg_type;
+	uint16_t pkg_numval;
+
+	uint8_t *pkg_types;
+	value_t *pkg_values;
 
 	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);
 	}
 
-	pv.head = (part_header_t *) buffer;
-	h_length = ntohs (pv.head->length);
-	h_type = ntohs (pv.head->type);
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_type = ntohs (tmp16);
+
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_length = ntohs (tmp16);
 
-	assert (h_type == TYPE_VALUES);
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_numval = ntohs (tmp16);
 
-	pv.num_values = (uint16_t *) (pv.head + 1);
-	h_num = ntohs (*pv.num_values);
+	assert (pkg_type == TYPE_VALUES);
 
-	if (h_num != ((h_length - 6) / 9))
+	exp_size = 3 * sizeof (uint16_t)
+		+ pkg_numval * (sizeof (uint8_t) + sizeof (value_t));
+	if (buffer_len < exp_size)
 	{
-		DBG ("`length' and `num of values' don't match");
+		WARNING ("network plugin: parse_part_values: "
+				"Packet too short: "
+				"Chunk of size %u expected, "
+				"but buffer has only %i bytes left.",
+				(unsigned int) exp_size, buffer_len);
 		return (-1);
 	}
 
-	pv.values_types = (uint8_t *) (pv.num_values + 1);
-	pv.values = (value_t *) (pv.values_types + h_num);
+	if (pkg_length != exp_size)
+	{
+		WARNING ("network plugin: parse_part_values: "
+				"Length and number of values "
+				"in the packet don't match.");
+		return (-1);
+	}
+
+	pkg_types = (uint8_t *) malloc (pkg_numval * sizeof (uint8_t));
+	pkg_values = (value_t *) malloc (pkg_numval * sizeof (value_t));
+	if ((pkg_types == NULL) || (pkg_values == NULL))
+	{
+		sfree (pkg_types);
+		sfree (pkg_values);
+		ERROR ("network plugin: parse_part_values: malloc failed.");
+		return (-1);
+	}
+
+	memcpy ((void *) pkg_types, (void *) buffer, pkg_numval * sizeof (uint8_t));
+	buffer += pkg_numval * sizeof (uint8_t);
+	memcpy ((void *) pkg_values, (void *) buffer, pkg_numval * sizeof (value_t));
+	buffer += pkg_numval * sizeof (value_t);
+
+	for (i = 0; i < pkg_numval; i++)
+	{
+		if (pkg_types[i] == DS_TYPE_COUNTER)
+			pkg_values[i].counter = ntohll (pkg_values[i].counter);
+		else if (pkg_types[i] == DS_TYPE_GAUGE)
+			pkg_values[i].gauge = ntohd (pkg_values[i].gauge);
+	}
 
-	for (i = 0; i < h_num; i++)
-		if (pv.values_types[i] == DS_TYPE_COUNTER)
-			pv.values[i].counter = ntohll (pv.values[i].counter);
+	*ret_buffer     = buffer;
+	*ret_buffer_len = buffer_len - pkg_length;
+	*ret_num_values = pkg_numval;
+	*ret_values     = pkg_values;
 
-	*ret_buffer     = (void *) (pv.values + h_num);
-	*ret_buffer_len = buffer_len - h_length;
-	*ret_num_values = h_num;
-	*ret_values     = pv.values;
+	sfree (pkg_types);
 
 	return (0);
 } /* int parse_part_values */
@@ -300,21 +553,40 @@ static int parse_part_values (void **ret_buffer, int *ret_buffer_len,
 static int parse_part_number (void **ret_buffer, int *ret_buffer_len,
 		uint64_t *value)
 {
-	part_number_t pn;
-	uint16_t len;
+	char *buffer = *ret_buffer;
+	int buffer_len = *ret_buffer_len;
 
-	pn.head = (part_header_t *) *ret_buffer;
-	pn.value = (uint64_t *) (pn.head + 1);
+	uint16_t tmp16;
+	uint64_t tmp64;
+	size_t exp_size = 2 * sizeof (uint16_t) + sizeof (uint64_t);
 
-	len = ntohs (pn.head->length);
-	if (len != 12)
-		return (-1);
-	if (len > *ret_buffer_len)
+	uint16_t pkg_length;
+	uint16_t pkg_type;
+
+	if (buffer_len < exp_size)
+	{
+		WARNING ("network plugin: parse_part_number: "
+				"Packet too short: "
+				"Chunk of size %u expected, "
+				"but buffer has only %i bytes left.",
+				(unsigned int) exp_size, buffer_len);
 		return (-1);
-	*value = ntohll (*pn.value);
+	}
+
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_type = ntohs (tmp16);
 
-	*ret_buffer = (void *) (pn.value + 1);
-	*ret_buffer_len -= len;
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_length = ntohs (tmp16);
+
+	memcpy ((void *) &tmp64, buffer, sizeof (tmp64));
+	buffer += sizeof (tmp64);
+	*value = ntohll (tmp64);
+
+	*ret_buffer = buffer;
+	*ret_buffer_len = buffer_len - pkg_length;
 
 	return (0);
 } /* int parse_part_number */
@@ -324,64 +596,92 @@ static int parse_part_string (void **ret_buffer, int *ret_buffer_len,
 {
 	char *buffer = *ret_buffer;
 	int   buffer_len = *ret_buffer_len;
-	part_string_t ps;
 
-	uint16_t h_length;
-	uint16_t h_type;
+	uint16_t tmp16;
+	size_t header_size = 2 * sizeof (uint16_t);
 
-	DBG ("ret_buffer = %p; ret_buffer_len = %i; output = %p; output_len = %i;",
-			*ret_buffer, *ret_buffer_len,
-			(void *) output, output_len);
+	uint16_t pkg_length;
+	uint16_t pkg_type;
 
-	ps.head = (part_header_t *) buffer;
+	if (buffer_len < header_size)
+	{
+		WARNING ("network plugin: parse_part_string: "
+				"Packet too short: "
+				"Chunk of at least size %u expected, "
+				"but buffer has only %i bytes left.",
+				(unsigned int) header_size, buffer_len);
+		return (-1);
+	}
 
-	h_length = ntohs (ps.head->length);
-	h_type = ntohs (ps.head->type);
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_type = ntohs (tmp16);
 
-	DBG ("length = %hu; type = %hu;", h_length, h_type);
+	memcpy ((void *) &tmp16, buffer, sizeof (tmp16));
+	buffer += sizeof (tmp16);
+	pkg_length = ntohs (tmp16);
 
-	if (buffer_len < h_length)
+	/* Check that packet fits in the input buffer */
+	if (pkg_length > buffer_len)
 	{
-		DBG ("packet is too short");
+		WARNING ("network plugin: parse_part_string: "
+				"Packet too big: "
+				"Chunk of size %hu received, "
+				"but buffer has only %i bytes left.",
+				pkg_length, buffer_len);
 		return (-1);
 	}
-	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')
+
+	/* Check that pkg_length is in the valid range */
+	if (pkg_length <= header_size)
 	{
-		DBG ("String does not end with a nullbyte");
+		WARNING ("network plugin: parse_part_string: "
+				"Packet too short: "
+				"Header claims this packet is only %hu "
+				"bytes long.", pkg_length);
 		return (-1);
 	}
 
-	if (output_len < (h_length - 4))
+	/* Check that the package data fits into the output buffer.
+	 * The previous if-statement ensures that:
+	 * `pkg_length > header_size' */
+	if ((pkg_length - header_size) > output_len)
 	{
-		DBG ("output buffer is too small");
+		WARNING ("network plugin: parse_part_string: "
+				"Output buffer too small.");
 		return (-1);
 	}
-	strcpy (output, ps.value);
 
-	DBG ("output = %s", output);
+	/* All sanity checks successfull, let's copy the data over */
+	output_len = pkg_length - header_size;
+	memcpy ((void *) output, (void *) buffer, output_len);
+	buffer += output_len;
 
-	*ret_buffer = (void *) (buffer + h_length);
-	*ret_buffer_len = buffer_len - h_length;
+	/* For some very weird reason '\0' doesn't do the trick on SPARC in
+	 * this statement. */
+	if (output[output_len - 1] != 0)
+	{
+		WARNING ("network plugin: parse_part_string: "
+				"Received string does not end "
+				"with a NULL-byte.");
+		return (-1);
+	}
+
+	*ret_buffer = buffer;
+	*ret_buffer_len = buffer_len - pkg_length;
 
 	return (0);
 } /* int parse_part_string */
 
 static int parse_packet (void *buffer, int buffer_len)
 {
-	part_header_t *header;
 	int status;
 
 	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));
@@ -389,75 +689,97 @@ static int parse_packet (void *buffer, int buffer_len)
 
 	while ((status == 0) && (buffer_len > sizeof (part_header_t)))
 	{
-		header = (part_header_t *) buffer;
+		uint16_t pkg_length;
+		uint16_t pkg_type;
+
+		memcpy ((void *) &pkg_type,
+				(void *) buffer,
+				sizeof (pkg_type));
+		memcpy ((void *) &pkg_length,
+				(void *) (buffer + sizeof (pkg_type)),
+				sizeof (pkg_length));
+
+		pkg_length = ntohs (pkg_length);
+		pkg_type = ntohs (pkg_type);
 
-		if (ntohs (header->length) > buffer_len)
+		if (pkg_length > buffer_len)
+			break;
+		/* Ensure that this loop terminates eventually */
+		if (pkg_length < (2 * sizeof (uint16_t)))
 			break;
 
-		if (header->type == htons (TYPE_VALUES))
+		if (pkg_type == TYPE_VALUES)
 		{
 			status = parse_part_values (&buffer, &buffer_len,
 					&vl.values, &vl.values_len);
 
 			if (status != 0)
-			{
-				DBG ("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");
 				plugin_dispatch_values (type, &vl);
 			}
 			else
 			{
-				DBG ("NOT dispatching values");
+				DEBUG ("network plugin: parse_packet:"
+						" NOT dispatching values");
 			}
+
+			sfree (vl.values);
 		}
-		else if (header->type == ntohs (TYPE_TIME))
+		else if (pkg_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 (pkg_type == TYPE_INTERVAL)
+		{
+			uint64_t tmp = 0;
+			status = parse_part_number (&buffer, &buffer_len, &tmp);
+			if (status == 0)
+				vl.interval = (int) tmp;
+		}
+		else if (pkg_type == TYPE_HOST)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.host, sizeof (vl.host));
 		}
-		else if (header->type == ntohs (TYPE_PLUGIN))
+		else if (pkg_type == TYPE_PLUGIN)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.plugin, sizeof (vl.plugin));
 		}
-		else if (header->type == ntohs (TYPE_PLUGIN_INSTANCE))
+		else if (pkg_type == TYPE_PLUGIN_INSTANCE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.plugin_instance, sizeof (vl.plugin_instance));
 		}
-		else if (header->type == ntohs (TYPE_TYPE))
+		else if (pkg_type == TYPE_TYPE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					type, sizeof (type));
 		}
-		else if (header->type == ntohs (TYPE_TYPE_INSTANCE))
+		else if (pkg_type == TYPE_TYPE_INSTANCE)
 		{
 			status = parse_part_string (&buffer, &buffer_len,
 					vl.type_instance, sizeof (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%04hx", pkg_type);
+			buffer = ((char *) buffer) + pkg_length;
 		}
 	} /* while (buffer_len > sizeof (part_header_t)) */
 
-	return (0);
+	return (status);
 } /* int parse_packet */
 
 static void free_sockent (sockent_t *se)
@@ -486,7 +808,7 @@ 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 +824,9 @@ 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 +845,10 @@ 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 +858,15 @@ 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;
 
-	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 +877,7 @@ 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 +885,20 @@ 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 +911,7 @@ 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 +931,20 @@ 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 +964,7 @@ 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 +981,12 @@ 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 +997,19 @@ 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 +1026,10 @@ 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 +1166,38 @@ static int network_add_sending_socket (const char *node, const char *service)
 	return (0);
 } /* int network_get_listen_socket */
 
-int network_receive (void)
+static void *dispatch_thread (void *arg)
+{
+  while (42)
+  {
+    receive_list_entry_t *ent;
+
+    /* Lock and wait for more data to come in */
+    pthread_mutex_lock (&receive_list_lock);
+    while ((listen_loop == 0)
+	&& (receive_list_head == NULL))
+      pthread_cond_wait (&receive_list_cond, &receive_list_lock);
+
+    /* Remove the head entry and unlock */
+    ent = receive_list_head;
+    if (ent != NULL)
+      receive_list_head = ent->next;
+    pthread_mutex_unlock (&receive_list_lock);
+
+    /* Check whether we are supposed to exit. We do NOT check `listen_loop'
+     * because we dispatch all missing packets before shutting down. */
+    if (ent == NULL)
+      break;
+
+    parse_packet (ent->data, ent->data_len);
+
+    sfree (ent);
+  } /* while (42) */
+
+  return (NULL);
+} /* void *receive_thread */
+
+static int network_receive (void)
 {
 	char buffer[BUFF_SIZE];
 	int  buffer_len;
@@ -828,7 +1210,7 @@ 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);
 	}
 
@@ -838,15 +1220,18 @@ 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);
 		}
 
 		for (i = 0; (i < listen_sockets_num) && (status > 0); i++)
 		{
+			receive_list_entry_t *ent;
+
 			if ((listen_sockets[i].revents & (POLLIN | POLLPRI)) == 0)
 				continue;
 			status--;
@@ -856,11 +1241,42 @@ 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);
 			}
 
-			parse_packet (buffer, buffer_len);
+			ent = malloc (sizeof (receive_list_entry_t));
+			if (ent == NULL)
+			{
+				ERROR ("network plugin: malloc failed.");
+				return (-1);
+			}
+			memset (ent, '\0', sizeof (receive_list_entry_t));
+
+			/* Hopefully this be optimized out by the compiler. It
+			 * might help prevent stupid bugs in the future though.
+			 */
+			assert (sizeof (ent->data) == sizeof (buffer));
+
+			memcpy (ent->data, buffer, buffer_len);
+			ent->data_len = buffer_len;
+
+			pthread_mutex_lock (&receive_list_lock);
+			if (receive_list_head == NULL)
+			{
+				receive_list_head = ent;
+				receive_list_tail = ent;
+			}
+			else
+			{
+				receive_list_tail->next = ent;
+				receive_list_tail = ent;
+			}
+			pthread_cond_signal (&receive_list_cond);
+			pthread_mutex_unlock (&receive_list_lock);
 		} /* for (listen_sockets) */
 	} /* while (listen_loop == 0) */
 
@@ -877,7 +1293,7 @@ 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 +1303,12 @@ 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 +1321,14 @@ 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 +1337,14 @@ 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 +1353,6 @@ 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 +1362,6 @@ 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 +1370,28 @@ 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 +1402,24 @@ 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 +1441,15 @@ 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 +1475,11 @@ 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 +1495,71 @@ 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 */);
+	/* Kill the listening thread */
+	if (receive_thread_id != (pthread_t) 0)
+	{
+		pthread_kill (receive_thread_id, SIGTERM);
+		pthread_join (receive_thread_id, NULL /* no return value */);
+		receive_thread_id = (pthread_t) 0;
+	}
+
+	/* Shutdown the dispatching thread */
+	if (dispatch_thread_id != (pthread_t) 0)
+		pthread_cond_broadcast (&receive_list_cond);
+
+	if (send_buffer_fill > 0)
+		flush_buffer ();
+
+	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' */
 
-	listen_thread = 0;
+	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)
 {
@@ -1084,20 +1570,40 @@ 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);
 
-	if ((listen_sockets_num != 0) && (listen_thread == 0))
+	if ((listen_sockets_num != 0) && (receive_thread_id == 0))
 	{
 		int status;
 
-		status = pthread_create (&listen_thread, NULL /* no attributes */,
-				receive_thread, NULL /* no argument */);
+		status = pthread_create (&dispatch_thread_id,
+				NULL /* no attributes */,
+				dispatch_thread,
+				NULL /* no argument */);
+		if (status != 0)
+		{
+			char errbuf[1024];
+			ERROR ("network: pthread_create failed: %s",
+					sstrerror (errno, errbuf,
+						sizeof (errbuf)));
+		}
 
+		status = pthread_create (&receive_thread_id,
+				NULL /* no attributes */,
+				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 +1613,4 @@ void module_register (void)
 	plugin_register_config ("network", network_config,
 			config_keys, config_keys_num);
 	plugin_register_init   ("network", network_init);
-}
+} /* void module_register */