diff --git a/src/node.c b/src/node.c
index 499651d..689ce52 100644
--- a/src/node.c
+++ b/src/node.c
@@ -43,6 +43,121 @@ neighbour_peer *get_random_neighbour() {
     return (neighbour_peer*) tmp->data;
 }
 
+// get data associated with id, if it doesn't exist return NULL
+pub_data *get_data(long id) {
+	list *tmp = data_list;
+	pub_data *data;
+
+	while(tmp != NULL) {
+		data = (pub_data*) tmp->data;
+
+		if(data->id == id)
+			return data;
+	}
+
+	return NULL;
+}
+
+// Take data as args and create a pub_data structure in the heap
+pub_data *copy_data(unsigned char len, long id, short seqno, char *data) {
+	pub_data *new_data = (pub_data*) malloc(sizeof(pub_data));
+	char *_data = (char*) malloc(len); 
+	new_data->length = len;
+	new_data->id = id;
+	new_data->seqno = seqno;
+	new_data->data = _data;
+	memcpy(_data, data, len);
+
+	return new_data;
+}
+
+// Add new data to data list
+void add_data(unsigned char len, long id, short seqno, char *data) {
+	// If id is the same as this node's id then we only update seqno
+	if(id == NODE_ID) {
+		pub_data *node_data = get_data(NODE_ID);
+
+		if(seqno >= node_data->seqno) {
+			node_data->seqno = seqno ^ 1;
+		}
+
+		return;
+	}
+
+	// Copy data
+	pub_data *new_data = copy_data(len, id, seqno, data);
+
+	if(data_list == NULL) {
+		// Update list
+		data_list = (list*) malloc(sizeof(list));
+		data_list->data = (void*) new_data;
+		data_list->next = NULL;
+
+		return;
+	}
+
+	// Find correct position for new data
+	list *tmp = data_list;
+	list *last = NULL;
+	list *new_node;
+	long cur_id;
+
+	while(tmp != NULL) {
+		cur_id = ((pub_data*) tmp->data)->id;
+
+		// If id is smaller than cur_id then the new data has to be added at this position
+		if(id < cur_id) {
+			// If last hasn't been set then the new data becomes the head of the list
+			if(last == NULL) {
+				// Update list
+				data_list = (list*) malloc(sizeof(list));
+				data_list->data = (void*) new_data;
+				data_list->next = tmp;
+
+				return;
+			}
+
+			// Else, we update the last node
+			new_node = (list*) malloc(sizeof(list));
+			new_node->data = (void*) new_data;
+			new_node->next = tmp; 
+			last->next = new_node;
+
+			return;
+		} else if(id == cur_id) {
+			// If data already exists for this id then we update it if it's seqno is greater than the one stored
+			pub_data *cur_data = (pub_data*) tmp->data;
+
+			if(seqno > cur_data->seqno) {
+				// Updata data
+				tmp->data = (void*) new_data;
+
+				// Free old data
+				free(cur_data);
+
+				return;
+			}
+
+			// seqno is smaller so the new data allocated is freed and nothing else is done
+			free(new_data);
+
+			return;
+		}
+
+		// Get next node in list
+		last = tmp;
+		tmp = tmp->next;
+	}
+
+	// If no correct position was found then the new data has to be added at the end of the list
+
+	// Update list
+	new_node = (list*) malloc(sizeof(list));
+	new_node->data = (void*) new_data;
+	new_node->next = NULL; 
+	last->next = new_node;
+}
+
 /* ---- Fin fonctions utilitaires ---- */
 
 // We need to make sure the TLV announces a length that will no go onto
@@ -61,7 +176,7 @@ int validate_tlv(char *data, int pos, short packet_len){
     unsigned char tlv_len = data[pos+1];
 
     // Check that the tlv does not exceed the packet length
-    if(pos + length >= packet_len)
+    if(pos + tlv_len >= packet_len)
         return -1;
 
     // Returns the type of the tlv or -1 if something went wrong
@@ -132,91 +247,172 @@ int update_neighbours(){
 };
 
 // We then look at the differents TLVs in the packet.
-void work_with_tlvs(char *data, short packet_len, struct sockaddr_in6 sender){
+int work_with_tlvs(char *data, short packet_len, struct sockaddr_in6 sender){
     int pos = 0;
-    unsigned char tlv_len;
-    tlv tmp_tlv;
+    unsigned char tlv_len, hash[16], warn[32];
+    tlv new_tlv, cur_tlv;
+    list *tmp_list;
+    pub_data *pdata;
 
     while(pos < packet_len) {
         switch(validate_tlv(data, pos, packet_len)) {
             case 0:
                 // We received a padding tlv so it is ignored
                 pos += 1;
+
                 break;
             case 1:
                 // We received a padding tlv so it is ignored
                 tlv_len = data[pos+1];
                 pos += tlv_len + 2;
+
                 break;
             case 2:
                 // We received a neighbour request so a random neighbor tlv has to be sent
-                tlv_len = data[pos+1];
-                pos += tlv_len + 2;
 
                 // Send a neighbour tlv
                 neighbour_peer *random = get_random_neighbour();
-                build_neighbour(&tmp_tlv, random->ip, random->port);
+                build_neighbour(&new_tlv, random->ip, random->port);
 
                 // NOT FINISHED - What packet is it added to?
-                add_tlv(packet, &tmp_tlv, 3);
-                break;
-            case 3:
-                // We received a neighbour tlv so a tlv network hash is sent to that address
-            	neighbour* cur_tlv = ((neighbour*) data) + pos;
-            	struct in6_addr ip = cur_tlv->ip;
-				short port = cur_tlv->port;
+                add_tlv(packet, &new_tlv, 3);
 
+                // The position is updated
                 tlv_len = data[pos+1];
                 pos += tlv_len + 2;
 
+                break;
+            case 3:
+                // We received a neighbour tlv so a tlv network hash is sent to that address
+            	cur_tlv.neighbour = (neighbour*) (data + pos);
+
                 // Build network hash
-                unsigned char hash[16];
-                hash_network(neighbour_list, hash);
-                build_network_hash(&tmp_tlv, hash);
+                build_network_hash(&new_tlv, data_list);
 
                 // NOT FINISHED - What packet is it added to?
-                add_tlv(packet, &tmp_tlv, 4);
+                add_tlv(packet, &new_tlv, 4);
+
+                // The position is updated
+                tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
                 break;
             case 4:
-                // We reveived a network hash tlv so
-                tlv_len = data[pos+1];
-                pos += tlv_len +2;
+                // We reveived a network hash tlv so we compare the hash with our own, if they differ we send a network state request tlv
+            	cur_tlv.network_hash = (network_hash*) (data + pos);
+            	hash_network(data_list, hash);
+
+            	if(memcmp(hash, cur_tlv.network_hash->network_hash, 16) == 0) {
+                	build_network_state_req(&new_tlv);
+                	// NOT FINISHED - What packet is it added to?
+                	add_tlv(packet, &new_tlv, 5);
+            	}
+
+                // The position is updated
+                tlv_len = data[pos+1];
+                pos += tlv_len + 2;
 
-                // NOT FINISHED - Where is network_hash?
-                build_neighbour(&tmp_tlv, network_hash);
-                // NOT FINISHED - What packet is it added to?
-                add_tlv(packet, &tmp_tlv, 4);
                 break;
             case 5:
                 // We received a network state request tlv so a series of tlv node hash have to be sent for each data known
-                pos += 2;
 
-                // NOT FINISHED - for each known data
-                list *tmp_list = data_list;
-                pub_data *tmp_data;
+                // for each known data build a node hash and add to packet
+                tmp_list = data_list;
 
                 while(tmp_list != NULL) {
-                	tmp_data = (pub_data*) tmp_list->data;
-                	build_node_hash(&tmp_tlv, tmp_data->id, tmp_data->seqno);
+                	pdata = (pub_data*) tmp_list->data;
+                	build_node_hash(&new_tlv, pdata->id, pdata->seqno, pdata->data);
+                	// NOT FINISHED - What packet is it added to?
+                	add_tlv(packet, &new_tlv, 4);
                 }
 
+                // The position is updated
+                pos += 2;
+
                 break;
             case 6:
-                // We received a node hash tlv
+                // We received a node hash tlv so if there is no entry for node_id in the data list or the hashes differ we send a node state request, if the hashes are identical nothing has to be done
+            	cur_tlv.node_hash = (node_hash*) (data + pos);
+            	pdata = get_data(cur_tlv.node_hash->node_id);
+
+            	// If data is found for this id then we check that both hashes are the same
+            	if(pdata != NULL) {
+            		// We hash the data stored in the data list
+            		hash_data(pdata, hash);
+
+            		// If both hashes are the same then nothing has to be done
+            		if(memcmp(hash, cur_tlv.node_hash->node_hash, 16) != 0) {
+            			// The position is updated
+            			tlv_len = data[pos+1];
+               			pos += 2;
+
+               			break;
+            		}
+
+            	}
+
+            	// If no pub_data was found or the hashes differ then we send a node state request
+            	build_node_state_req(&new_tlv, cur_tlv.node_hash->node_id);
+            	// NOT FINISHED - What packet is it added to?
+            	add_tlv(packet, &new_tlv, 7);
+
+            	// The position is updated
+            	tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
                 break;
             case 7:
-                // We received a node state request tlv
+                // We received a node state request tlv so a node state tlv for this node id has to be sent, if no pub_data exists for this id nothing is sent
+            	cur_tlv.node_state_req = (node_state_req*) (data + pos);
+            	pdata = get_data(cur_tlv.node_state_req->node_id);
+
+            	if(pdata != NULL) {
+            		build_node_state(&new_tlv, pdata->id, pdata->seqno, pdata->data, pdata->length);
+            		// NOT FINISHED - What packet is it added to?
+            		add_tlv(packet, &new_tlv, 8);
+            	}
+
+            	// The position is updated
+            	tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
                 break;
             case 8:
-                // We received a node state tlv
+                // We received a node state tlv so we add it to the data list or update the data stored
+            	cur_tlv.node_state = (node_state*) (data + pos);
+
+            	add_data(cur_tlv.node_state->length - 26, cur_tlv.node_state->node_id, cur_tlv.node_state->seqno, cur_tlv.node_state->data);
+
+            	// The position is updated
+            	tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
                 break;
             case 9:
                 // We received a warning tlv so it's message is printed
+            	cur_tlv.warning = (warning*) (data + pos);
+            	
+            	// Print exactly new_tlv.length characters from new_tlv.message
+            	sprintf(warn, ">> WARNING:\n%%.%ds", cur_tlv.warning->length + 1);
+            	printf(warn, cur_tlv.warning->message);
+
+            	// The position is updated
+            	tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
                 break;
             default:
-                return ;
+            	// A malformed packet was found so we stop looking for more packets and send a warning tlv
+            	strcpy(warn, "Packet is malformed.");
+            	build_warning(&new_tlv, warn, strlen(warn));
+            	// NOT FINISHED - What packet is it added to?
+            	add_tlv(packet, &new_tlv, 9);
+
+                return -1;
         }
     }
+
+    return 0;
 }
 
 // We listen forever for new paquets;
diff --git a/src/node.h b/src/node.h
index d4ba94b..630a93e 100644
--- a/src/node.h
+++ b/src/node.h
@@ -90,4 +90,13 @@ int len_list(list *l);
 
 neighbour_peer *get_random_neighbour();
 
+// get data associated with id, if it doesn't exist return NULL
+pub_data *get_data(long id);
+
+// Take data as args and create a pub_data structure in the heap
+pub_data *copy_data(unsigned char len, long id, short seqno, char *data);
+
+// add new data to data list
+void add_data(unsigned char len, long id, short seqno, char *data);
+
 #endif
diff --git a/src/tlv.c b/src/tlv.c
index 2284815..c93436a 100644
--- a/src/tlv.c
+++ b/src/tlv.c
@@ -79,7 +79,7 @@ int build_neighbour(tlv *tlv, struct in6_addr ip, short port) {
 	return 0;
 }
 
-int build_network_hash(tlv *tlv, char *hash) {
+int build_network_hash(tlv *tlv, list *data_list) {
 	network_hash *new = (network_hash*) malloc(sizeof(network_hash));
 
 	if(new == NULL)
@@ -87,7 +87,7 @@ int build_network_hash(tlv *tlv, char *hash) {
 
 	new->type = 4;
 	new->length = 16;
-	memcpy(new->network_hash, hash, 16);
+	hash_network(data_list, new->network_hash);
 
 	tlv->network_hash = new;
 
@@ -108,7 +108,7 @@ int build_network_state_req(tlv *tlv) {
 	return 0;
 }
 
-int build_node_hash(tlv *tlv, long node_id, short seqno, char *hash) {
+int build_node_hash(tlv *tlv, long node_id, short seqno, char *data) {
 	node_hash *new = (node_hash*) malloc(sizeof(node_hash));
 
 	if(new == NULL)
@@ -118,7 +118,9 @@ int build_node_hash(tlv *tlv, long node_id, short seqno, char *hash) {
 	new->length = 26;
 	new->node_id = node_id;
 	new->seqno = seqno;
-	memcpy(new->node_hash, hash, 16);
+
+	pub_data pdata = (pub_data) {.id = node_id, .seqno = seqno, .data = data};
+	hash_data(&pdata, new->node_hash);
 
 	tlv->node_hash = new;
 
@@ -140,9 +142,9 @@ int build_node_state_req(tlv *tlv, long node_id) {
 	return 0;
 }
 
-int build_node_state(tlv *tlv, long node_id, short seqno, char *node_hash, char *data) {
+int build_node_state(tlv *tlv, long node_id, short seqno, char *data, size_t data_len) {
 	node_state *new = (node_state*) malloc(sizeof(node_state));
-	int len = strlen(data);
+	int len = data_len + 26;
 
 	if(new == NULL)
 		return -1;
@@ -157,17 +159,19 @@ int build_node_state(tlv *tlv, long node_id, short seqno, char *node_hash, char
 	new->length = 26 + len;
 	new->node_id = node_id;
 	new->seqno = seqno;
-	memcpy(new->node_hash, node_hash, 16);
 	memcpy(new->data, data, len);
 
+	pub_data pdata = (pub_data) {.id = node_id, .seqno = seqno, .data = data};
+	hash_data(&pdata, new->node_hash);
+
 	tlv->node_state = new;
 
 	return 0;
 }
 
-int build_warning(tlv *tlv, char *message) {
+int build_warning(tlv *tlv, char *message, size_t message_len) {
 	warning *new = (warning*) malloc(sizeof(warning));
-	int len = strlen(message);
+	int len = message_len;
 
 	if(new == NULL)
 		return -1;
diff --git a/src/tlv.h b/src/tlv.h
index c9a3d00..33bbaf5 100644
--- a/src/tlv.h
+++ b/src/tlv.h
@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include "parser.h"
 #include "hash.h"
+#include "node.h"
 
 #define LEN_NEIGHBOUR_REQ 0
 #define LEN_NEIGHBOUR 18
@@ -33,7 +34,7 @@ typedef struct pad1 {
 typedef struct padn {
 	unsigned char type;
 	unsigned char length;
-	char mbz[256];
+	char *mbz;
 } padn;
 
 // 2 octets
@@ -117,11 +118,11 @@ int build_pad1(tlv *tlv);
 int build_padn(tlv *tlv, size_t len);
 int build_neighbour_req(tlv *tlv);
 int build_neighbour(tlv *tlv, struct in6_addr ip, short port);
-int build_network_hash(tlv *tlv, char *network_hash);
+int build_network_hash(tlv *tlv, list *data_list);
 int build_network_state_req(tlv *tlv);
-int build_node_hash(tlv *tlv, long node_id, short seqno, char *node_hash);
+int build_node_hash(tlv *tlv, long node_id, short seqno, char *data);
 int build_node_state_req(tlv *tlv, long node_id);
-int build_node_state(tlv *tlv, long node_id, short seqno, char *node_hash, char *data);
-int build_warning(tlv *tlv, char *message);
+int build_node_state(tlv *tlv, long node_id, short seqno, char *data, size_t data_len);
+int build_warning(tlv *tlv, char *message, size_t message_len);
 
 #endif