diff --git a/Notes.md b/Notes.md
index c4d7d4b..f0fd541 100644
--- a/Notes.md
+++ b/Notes.md
@@ -7,3 +7,9 @@ s ⊕ n = (s + n) and 65535
 
 s ≼ s ′ lorsque ((s ′ − s) mod 2 16 ) < 32768
 s ≼ s ′ lorsque ((s ′ − s) and 32768) = 0
+
+-------
+
+jch.irif.fr port UDP 1212
+
+http://jch.irif.fr:8082/
diff --git a/src/Notes.md b/src/Notes.md
new file mode 100644
index 0000000..5137b8a
--- /dev/null
+++ b/src/Notes.md
@@ -0,0 +1,4 @@
+# Notes et recherches sur le projet
+
+Telecharger la librarie OpenSSl avec 'sudo apt-get install libssl-dev'
+Utiliser 'gcc -o {exec} {fichier.c} -lssl -lcrypto' pour utiliser la librarie OpenSSL
\ No newline at end of file
diff --git a/src/README.md b/src/README.md
new file mode 100644
index 0000000..084ce3a
--- /dev/null
+++ b/src/README.md
@@ -0,0 +1,5 @@
+# dazibao
+
+Le but de ce projet est d’implémenter un dazibao (« journal à grandes lettres »), semblable à
+un « mur » de réseau social, mais de façon complètement distribuée. Le protocole est basé sur un
+algorithme non-fiable d’inondation.
\ No newline at end of file
diff --git a/src/hash.c b/src/hash.c
new file mode 100644
index 0000000..287e2c4
--- /dev/null
+++ b/src/hash.c
@@ -0,0 +1,60 @@
+#include "hash.h"
+
+// Hash a single data
+void hash_data(pub_data *data, unsigned char *buf) {
+	// All three fields are concatenated into a single buffer
+	int totlen = data->length + 10;
+	unsigned char concat[totlen];
+	concat_data(data, concat);
+
+	// The resulting buf is hashed and put into a buffer
+	unsigned char hash[SHA256_DIGEST_LENGTH];
+	SHA256(concat, totlen, hash);
+
+	// Put truncated hash into buf 
+	hash_trunc(hash, buf);
+}
+
+// Hash every data contained in data_list then return a network hash
+void hash_network(list *data_list, unsigned char *buf) {
+	unsigned char *concat = (unsigned char*) malloc(0);
+	unsigned char hash[SHA256_DIGEST_LENGTH];
+	int totlen = 0;
+	list *tmp = data_list;
+
+	// Hash every known data and concatenate it to buffer concat
+	while(tmp != NULL) {
+		hash_data((pub_data*) tmp->data, hash);
+		concat_hash(concat, hash, totlen);
+		totlen += 16;
+		tmp = tmp->next;
+	}
+
+	// Hash all of concat to obtain the network hash
+	SHA256(concat, totlen, hash);
+
+	// Put truncated hash into buf 
+	hash_trunc(hash, buf);
+
+	// Get rid of concat
+	free(concat);
+}
+
+// Truncate 32 octet hash to 16 octets
+void hash_trunc(unsigned char *hash32oct, unsigned char *buf) {
+	// Copy the first 16 octets from hash32oct
+	memcpy(buf, hash32oct, 16);
+}
+
+// Concat all fields of data and put them in buf
+void concat_data(pub_data *data, unsigned char *buf) {
+	memcpy(buf, &(data->id), 8);
+	memcpy(buf+8, &(data->seqno), 2);
+	memcpy(buf+10, data->data, data->length);
+}
+
+// Concat hash2 to hash1 (hash1 is modified)
+void concat_hash(unsigned char *hash1, unsigned char *hash2, size_t size) {
+	hash1 = (unsigned char*) realloc(hash1, size + 16);
+	memcpy(hash1+size, hash2, 16);
+}
\ No newline at end of file
diff --git a/src/hash.h b/src/hash.h
new file mode 100644
index 0000000..358c7b5
--- /dev/null
+++ b/src/hash.h
@@ -0,0 +1,23 @@
+#ifndef HASH_H
+#define HASH_H
+
+#include <openssl/sha.h>
+#include "node.h"
+#include "tlv.h"
+
+// Hash a single data
+void hash_data(pub_data *data, unsigned char *buf);
+
+// Hash every data contained in data_list then return a network hash
+void hash_network(list *data_list, unsigned char *buf);
+
+// Truncate 32 octet hash to 16 octets
+void hash_trunc(unsigned char *hash256bit, unsigned char *buf);
+
+// Concat all fields of data and put them in buf
+void concat_data(pub_data *data, unsigned char *buf);
+
+// Concat hash2 to hash1 (hash1 is modified)
+void concat_hash(unsigned char *hash1, unsigned char *hash2, size_t size);
+
+#endif
\ No newline at end of file
diff --git a/src/install.sh b/src/install.sh
new file mode 100755
index 0000000..bf11d28
--- /dev/null
+++ b/src/install.sh
@@ -0,0 +1 @@
+sudo apt-get install libssl-dev
\ No newline at end of file
diff --git a/src/node.c b/src/node.c
index fdfb6fe..fbe2830 100644
--- a/src/node.c
+++ b/src/node.c
@@ -1,79 +1,371 @@
 // This is the main file of the Dazibao project. It represents the node, and
 // handles all of the main logic, including the network connexions.
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <time.h>
 
+#include "tlv.h"
+#include "node.h"
 
-// Will return a packet when we receive one that's valid.
-packet listen_for_packets(){
+/* ----  Fonctions utilitaires  ---- */
 
+// Get list length
+int len_list(list *l) {
+	int len = 0;
+	list *tmp = l;
+
+	while(tmp != NULL) {
+		tmp = tmp->next;
+		len++;
+	}
+
+	return len;
 }
 
-int validate_tlvs(union tlv tlv_to_validate){
-    // We need to make sure the TLV announces a length that will no go onto
-    // another tlv, as we might end up reading bullshit.
+// Get a random neighbour
+neighbour_peer *get_random_neighbour() {
+	// Get a random number
+    time_t t;
+    srand((unsigned) time(&t));
+    int n = rand() % len_list(neighbour_list);
+
+    // Get nth neighbour
+    list *tmp = neighbour_list;
+
+    for(int i=0; i<n; i++) {
+    	tmp = tmp->next;
+    }
+
+    return (neighbour_peer*) tmp->data;
 }
 
-void work_with_tlvs(struct tlvs_list receivied_tlvs){
+/* ---- Fin fonctions utilitaires ---- */
 
-    // For every TLV,
-        // We make sure the TLV is legal.
-        if(!validate_tlvs(tlv)){
-            perror(">> Invalid TLV receivied, is will be ignored.");
+int send_tlv(struct tlv tlv_to_send, int tlv_type, struct sockaddr_in6 * dest_list[], int dest_list_size, int sock_num){
+	debug_print("Building packet to send a TLV.");
+
+	// We first need to build the packet,
+	char packet_buff[1024];
+	struct packet pack;
+
+	pack.magic = 95;
+	pack.version = 1;
+	if(sizeof(tlv_to_send) > 1020){
+		debug_print("Unable to send TLV, the size is bigger than 1020 bits.");
+		return -1;
+	} else {
+		pack.length = sizeof(tlv_to_send);
+		strcpy(pack.body, (char) tlv_to_send);
+	}
+
+	// Casting the struct to a buffer.
+	packet_buff = (char *) pack;
+
+	debug_print("Packet has been built.");
+
+    // Vectorized buffer
+    struct iovec vec_buff = { .iov_len = sizeof(packet_buff), .iov_base = packet_buff };
+
+	int error_while_sending = 0;
+
+	// For every dest
+	for (size_t i = 0; i < dest_list_size; i++) {
+		// Creating the struct to send out with sendmsg
+		struct msghdr packet_tlv_send_out = {
+			.msg_name = &dest_list[i],
+			.msg_namelen = sizeof(dest_list[i]),
+			.msg_iov = &vec_buff,
+			.msg_iovlen = 1 // We have only one iovec buffer. But if we had 2, we would write 2.
+		};
+
+		response_code = sendmsg((int) sock_num, &packet_tlv_send_out, 0);
+		if (response_code < 0) {
+			debug_print("Unable to send out the packet to peer %i", i);
+			error_while_sending = 1;
+			continue;
+		} else if (response_code < sizeof(packet_tlv_send_out)) {
+			debug_print("Sent out only part of the packet.");
+			error_while_sending = 1;
+			continue;
+		} else {
+			debug_print("Send out packet to peer %i", i);
+		}
+	}
+
+	if (error_while_sending == 1) {
+		debug_print("Error occured while sending out a packet.");
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
+// We need to make sure the TLV announces a length that will no go onto
+// another tlv, as we might end up reading bullshit.
+int validate_tlv(char *data, int pos, short packet_len){
+    char type = data[pos];
+
+    // Nothing to do in this case
+    if(type == 0)
+        return 0;
+
+    // Check that we can read a length
+    if(pos + 1 >= packet_len)
+        return -1;
+
+    unsigned char tlv_len = data[pos+1];
+
+    // Check that the tlv does not exceed the packet length
+    if(pos + length >= packet_len)
+        return -1;
+
+    // Returns the type of the tlv or -1 if something went wrong
+    switch(type) {
+        case 1:
+            return 1;
+        case 2:
+            if(tlv_len != LEN_NEIGHBOUR_REQ) return -1;
+            return 2;
+        case 3:
+            if(tlv_len != LEN_NEIGHBOUR) return -1;
+            return 3;
+        case 4:
+            if(tlv_len != LEN_NETWORK_HASH) return -1;
+            return 4;
+        case 5:
+            if(tlv_len != LEN_NETWORK_STATE_REQ) return -1;
+            return 5;
+        case 6:
+            if(tlv_len != LEN_NODE_HASH) return -1;
+            return 6;
+        case 7:
+            if(tlv_len != LEN_NODE_STATE_REQ) return -1;
+            return 7;
+        case 8:
+            if(tlv_len < MIN_LEN_NODE_STATE || tlv_len > MAX_LEN_NODE_STATE) return -1;
+            return 8;
+        case 9:
+            return 9;
+        default:
+            return -1;
+    }
+}
+
+// For every packet recivied,
+// then we make sure it's conform
+// We then extract the data from it to make it easy to work with
+int check_header(char * req[], int buffer_size, struct packet * packet_to_return){
+
+    packet * packet_to_return = (packet*) req;
+
+    // We need to check a few things ;
+    // The first byte must be worth 95,
+    if (packet_to_return->magic != 95) {
+        perror(">> The magic number of the packet is no good.");
+        return -1;
+    }
+
+    // The second byte must be worth 1,
+    if (packet_to_return->version != 1) {
+        perror(">> The version number of the packet is no good.");
+        return -1;
+    }
+
+    if (packet_to_return.length + 4 > buffer_size  ) {
+        perror(">> The packet length is bigger than the UDP datagram, which is not possible with the current laws of physics.");
+        return -1;
+    }
+
+    return 0;
+}
+
+// If the sender is not in the neighbourhood, and we have 15 neighbours, we
+// ignore the packet. Otherwise, we add him to the neighbourhood, marked as
+// temporary.
+int update_neighbours(){
+    return 0;
+};
+
+// We then look at the differents TLVs in the packet.
+void work_with_tlvs(char *data, short packet_len, struct sockaddr_in6 sender){
+    int pos = 0;
+    unsigned char tlv_len;
+    tlv tmp_tlv;
+
+    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);
+
+                // 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;
+
+                tlv_len = data[pos+1];
+                pos += tlv_len + 2;
+
+                // Build network hash
+                unsigned char hash[16];
+                hash_network(neighbour_list, hash);
+                build_network_hash(&tmp_tlv, hash);
+
+                // NOT FINISHED - What packet is it added to?
+                add_tlv(packet, &tmp_tlv, 4);
+                break;
+            case 4:
+                // We reveived a network hash tlv so
+                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;
+
+                while(tmp_list != NULL) {
+                	tmp_data = (pub_data*) tmp_list->data;
+                	build_node_hash(&tmp_tlv, tmp_data->id, tmp_data->seqno);
+                }
+
+                break;
+            case 6:
+                // We received a node hash tlv
+                break;
+            case 7:
+                // We received a node state request tlv
+                break;
+            case 8:
+                // We received a node state tlv
+                break;
+            case 9:
+                // We received a warning tlv so it's message is printed
+                break;
+            default:
+                return ;
+        }
+    }
+}
+
+// We listen forever for new paquets;
+void listen_for_packets(){
+
+    // Create new socket for UDP
+    int s = socket(AF_INET6, SOCK_DGRAM, 0);
+
+    if(s < 0) {
+        perror(">> Error, cannot create socket.");
+        perror(">> Exiting...");
+        exit(1);
+    }
+
+    struct sockaddr_in6 server;
+    memset(&server, 0, sizeof(server));
+
+    server.sin6_family = AF_INET6;
+    server.sin6_port = htons(LISTEN_PORT);
+    int rc = bind(s, (struct sockaddr*)&server, sizeof(server));
+    if(rc < 0) {
+        perror(">> Error, cannot bind socket to choosen port.");
+        perror(">> Exiting...");
+        exit(1);
+    }
+
+    // A paquet has at most a length of 1024 bytes
+    char req[1024];
+    struct sockaddr_in6 sender;
+    struct iovec io = { .iov_len = 1024, .iov_base = req };
+    struct msghdr msg_to_receive = {
+        .msg_name = &sender,
+        .msg_namelen = sizeof(sender),
+        .msg_iov = &io,
+        .msg_iovlen = 1
+    };
+    while(1){
+        memset(req, '\0', 1024);
+
+        rc = recvmsg(s, &msg_to_receive, 0);
+        if(rc < 0) {
+            perror(">> Error while receiving a new datagram.");
+            perror(">> Ignoring, continuing...");
+            continue;
         }
 
-    // Switch
+        printf(">> New paquet received :\n");
+        printf("%s\n", req);
 
-    // TLV Network Hash
-        // We calculate a network hash,
+        // TODO : Here, we need to fork.
 
-        // We compare both,
+        // We verify the received packet is well formated,
+        // and we return it in the struct designed to work with it.
+        struct packet * formated_rec_datagram;
+        if(check_header(&req, 1024, formated_rec_datagram) < 0){
+            perror(">> Error while checking the header, aborting this packet, by choice, and conviction.");
+            continue;
+        }
 
-        // If they differ, we send a TLV Network State Request
-        // back to the sender.
+        // TODO : Add the neighbour check here.
 
-    // TLV Network State Request
-        // We check our neighbourhood, and for each peer, we send back
-        // to the sender a TLV Node Hash
-
-    // TLV Node hash
-        // We get a hash _h_ for the node _l_
-        // If we don't have an entry for _l_, or if we have the same one as the
-        // on we just receivied, we send out a TLV Node State Request back.
-
-    // TLV Node State
-        // We get a hash _h_, sequence number _s_, data _d_ for node _l_.
-        // We compute a network hash,
-        // We compare the hash, if they differ, then with l',s',d' our data and
-        // h' the corresponding hash,
-            // if _l_ is our own node id, then
-                // if s >> s' then we update our sequence number to s ⊕ 1 mod 2^16
-            // If it's another's node id, then
-                // If there is no entry for the sender,
-                // we store the entry in our data table.
+        // struct tlv_list received_tlvs;
+        // if (validate_tlvs(formated_rec_datagram) < 0)
+        int nbr_success_tlv = work_with_tlvs(formated_rec_datagram, &req, sender);
+        if (nbr_success_tlv < 0){
+            perror(">> Error while treating the TLVs of the packet.");
+            printf(">> Managed to deal with %i TLVs\n", -nbr_success_tlv );
+        } else {
+            printf(">> Done working with the TLVs of the packet, listenin for new packets.\n");
+        }
+    }
 }
 
-int main(int argc, char const *argv[]) {
+int main(int argc, const char *argv[]) {
+    int cont = 1;
 
-    while(CONTINUE){
+    while(cont){
 
         // We create the neighbourhood table
+        neighbour_peer neighbour_list[NEIGHBOUR_MAX];
         // We create the message table
+
         // We create our own message.
 
         // Listen for incoming packets
         listen_for_packets();
-        // For every packet recivied, we fork,
-        // then we make sure it's conform
-        // We then extract the data from it to make it easy to work with
-        check_header();
-        // If the sender is not in the neighbourhood, and we have 15 neighbours, we
-        // ignore the packet. Otherwise, we add him to the neighbourhood, marked as
-        // temporary.
-        update_neighbours();
-        // We then look at the differents TLVs in the packet.
-        work_with_tlvs();
 
+        // This is in it's own fork.
         time_t delay = time(NULL) + 20;
-        while(! (delay < time(NULL)){
+        while(! (delay < time(NULL))) {
             // Theses functions are there for general book-keeping,and run in there own
             // thread, being run every 20 seconds.
             // Every 20 sec, if we have less than 5 neighbours, we ask for more peers
diff --git a/src/node.h b/src/node.h
index 21329be..0f7e2c6 100644
--- a/src/node.h
+++ b/src/node.h
@@ -1,19 +1,93 @@
 // Define constants
 
+#ifndef NODE_H
+#define NODE_H
+
+#include <stdlib.h>
+#include <time.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+
+#include "tlv.h"
+#include "hash.h"
+
+// On which port do we listen to
+#define LISTEN_PORT 1212
+
+// The node ID
+#define NODE_ID 42675882021843277
+
+// The number of neighbours
+// The neighbour table has 15 entries
+#define NEIGHBOUR_MAX 15
+
+/* la table de voisins, qui est indexée par adresses de socket (des paires (IP, Port)),
+ * et dont chaque entrée contient un booléen indiquant si le pair est permanent
+ * (configuré au lancement) ou transitoire, et la date de dernière réception d’un
+ * paquet de la part de ce pair ;
+*/
+typedef struct neighbour_peer {
+    struct in6_addr ip;
+    short port;
+    char is_temporary;
+    struct timeval last_seen;
+} neighbour_peer;
+
+// The strucuture to hold the messages
+/* It's a list of triplets, (Li,Si,Di)
+ * Li : The Node ID of the publisher 64 bits
+ * Si : the sequence number 16 bits
+ * Di : the data of the message 192 bytes
+*/
+
+typedef struct pub_data {
+	unsigned char length;
+    long id;
+    short seqno;
+    char *data;
+} pub_data;
+
+// General list
+typedef struct list {
+	void *data;
+	void *next;
+} list;
+
+// Static variables
+static list *data_list;
+static list *neighbour_list;
+
+// TODO
 
 // fonctions signatures
 void listen_for_packets();
 
-void check_header();
+int check_header(char * received_datagram[], int len, struct packet pack);
 
-void update_neighbours();
+int validate_tlvs(struct packet * pack, struct tlv_list * tlv_l);
 
-void work_with_tlvs();
+int update_neighbours();
 
-int validate_tlvs();
+int work_with_tlvs(struct packet received_packet, char * data_from_packet[], struct sockaddr_in6 sender);
+
+void add_tlv(packet *packet, tlv *tlv, char type);
+
+int send_packet();
+
+/* Takes a TLV and sends it over to everyone in the list of addresses.
+ * Returns -1 in case of error, 0 otherwise.
+ */
+int send_tlv(struct tlv tlv_to_send, int tlv_type, struct sockaddr_in6 * dest_list[], int dest_list_size, int socket_num);
+
+/* Takes a list of TLV and sends them over to everyone in the list of addresses.
+ * Returns -1 in case of error, 0 otherwise.
+ */
+int send_tlvs(struct list * tlv_list, int tlv_type, struct sockaddr_in6 * dest_list[], int dest_list_size, int socket_num);
 
 // threaded functions
-
 void t_ask_for_more_peers();
 
 void t_update_neighbours();
@@ -21,6 +95,8 @@ void t_update_neighbours();
 void t_get_network_state();
 
 // Helper functions
-char * hash();
+int len_list(list *l);
 
-short * get_seq_no(short s, int n);
+neighbour_peer *get_random_neighbour();
+
+#endif
diff --git a/src/parser.c b/src/parser.c
new file mode 100644
index 0000000..e4acb03
--- /dev/null
+++ b/src/parser.c
@@ -0,0 +1,32 @@
+#include "parser.h"
+
+// retourne le type de commande à exécuter
+cmd_token parse_cmd() {
+	char buf[198], cmd[5], arg[193];
+	cmd_token token;
+	token.type = ERROR;
+	memset(token.arg, 0, 193);
+
+	if(fgets(buf, 198, stdin) == NULL)
+		return token;
+
+	// cmd sera le premier mot rencontré et arg la suite de mots après celui ci,
+	// si les deux variables ne sont pas remplies alors il y a une erreur
+	if(sscanf(buf, "%s %[^\t\n]", cmd, arg) != 2)
+		return token;
+
+	if(strcmp("req", cmd) == 0) {
+		if(strcmp("neighbour", arg) == 0)
+			token.type = NEIGHBOUR_REQ;
+		else if(strcmp("network state", arg) == 0)
+			token.type = NETWORK_STATE_REQ;
+		else if(strcmp("node state", arg) == 0)
+			token.type = NODE_STATE_REQ;
+	} else if(strcmp("post", cmd) == 0) {
+		token.type = POST;
+		//arg[192] = 0;
+		strcpy(token.arg, arg);
+	}
+
+	return token;
+}
diff --git a/src/parser.h b/src/parser.h
new file mode 100644
index 0000000..b373a0d
--- /dev/null
+++ b/src/parser.h
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <string.h>
+
+#ifndef PARSER_H
+#define PARSER_H
+
+typedef enum cmd_type {
+	NEIGHBOUR_REQ, NETWORK_STATE_REQ, NODE_STATE_REQ, POST, ERROR
+} cmd_type;
+
+typedef struct cmd_token {
+	cmd_type type;
+	char arg[193];
+} cmd_token;
+
+// retourne le type de commande à exécuter
+cmd_token parse_cmd();
+
+#endif
\ No newline at end of file
diff --git a/src/tlv.c b/src/tlv.c
new file mode 100644
index 0000000..e19cfd9
--- /dev/null
+++ b/src/tlv.c
@@ -0,0 +1,188 @@
+#include "tlv.h"
+
+// creer un tlv
+int build_tlv(tlv *tlv, cmd_token token) {
+	switch(token.type) {
+		case NEIGHBOUR_REQ:
+			// a remplir
+			break;
+		case NETWORK_STATE_REQ:
+			// a remplir
+			break;
+		case NODE_STATE_REQ:
+			// a remplir
+			break;
+		case POST:
+			// a remplir
+			break;
+		case ERROR:
+			printf("Wrong format, use 'req {neighbour | network state | node state}' or 'post {message}'");
+			break;
+	}
+}
+
+int build_pad1(tlv *tlv) {
+	pad1 *new = (pad1*) malloc(sizeof(pad1));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 0;
+
+	tlv->pad1 = new;
+
+	return 0;
+}
+
+int build_padn(tlv *tlv, size_t len) {
+	padn *new = (padn*) malloc(sizeof(padn));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 1;
+	new->length = len;
+	new->mbz = (char*) calloc(sizeof(char), len);
+
+	tlv->padn = new;
+
+	return 0;
+}
+
+int build_neighbour_req(tlv *tlv) {
+	neighbour_req *new = (neighbour_req*) malloc(sizeof(neighbour_req));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 2;
+	new->length = 0;
+
+	tlv->neighbour_req = new;
+
+	return 0;
+}
+
+int build_neighbour(tlv *tlv, struct in6_addr ip, short port) {
+	neighbour *new = (neighbour*) malloc(sizeof(neighbour));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 3;
+	new->length = 18;
+	new->ip = ip;
+	new->port = port;
+
+	tlv->neighbour = new;
+
+	return 0;
+}
+
+int build_network_hash(tlv *tlv, char *hash) {
+	network_hash *new = (network_hash*) malloc(sizeof(network_hash));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 4;
+	new->length = 16;
+	memcpy(new->network_hash, hash, 16);
+
+	tlv->network_hash = new;
+
+	return 0;
+}
+
+int build_network_state_req(tlv *tlv) {
+	network_state_req *new = (network_state_req*) malloc(sizeof(network_state_req));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 5;
+	new->length = 0;
+
+	tlv->network_state_req = new;
+
+	return 0;
+}
+
+int build_node_hash(tlv *tlv, long node_id, short seqno, char *hash) {
+	node_hash *new = (node_hash*) malloc(sizeof(node_hash));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 6;
+	new->length = 26;
+	new->node_id = node_id;
+	new->seqno = seqno;
+	memcpy(new->node_hash, hash, 16);
+
+	tlv->node_hash = new;
+
+	return 0;
+}
+
+int build_node_state_req(tlv *tlv, long node_id) {
+	node_state_req *new = (node_state_req*) malloc(sizeof(node_state_req));
+
+	if(new == NULL)
+		return -1;
+
+	new->type = 7;
+	new->length = 8;
+	new->node_id = node_id;
+
+	tlv->node_state_req = new;
+
+	return 0;
+}
+
+int build_node_state(tlv *tlv, long node_id, short seqno, char *node_hash, char *data) {
+	node_state *new = (node_state*) malloc(sizeof(node_state));
+	int len = strlen(data);
+
+	if(new == NULL)
+		return -1;
+
+	// en mettant cet octet à 0 on est surs de traiter un champ data de taille 192 max
+	if(len > 192) {
+		data[192] = 0;
+		len = 192;
+	}
+
+	new->type = 8;
+	new->length = 26 + len;
+	new->node_id = node_id;
+	new->seqno = seqno;
+	memcpy(new->node_hash, node_hash, 16);
+	memcpy(new->data, data, len);
+
+	tlv->node_state = new;
+
+	return 0;
+}
+
+int build_warning(tlv *tlv, char *message) {
+	warning *new = (warning*) malloc(sizeof(warning));
+	int len = strlen(message);
+
+	if(new == NULL)
+		return -1;
+
+	// en mettant cet octet à 0 on est surs de traiter un champ message de taille 256 max
+	if(len > 256) {
+		message[256] = 0;
+		len = 256;
+	}
+
+	new->type = 9;
+	new->length = len;
+	memcpy(new->message, message, len);
+
+	tlv->warning = new;
+
+	return 0;
+}
diff --git a/src/tlv.h b/src/tlv.h
new file mode 100644
index 0000000..c9a3d00
--- /dev/null
+++ b/src/tlv.h
@@ -0,0 +1,127 @@
+#ifndef TLV_H
+#define TLV_H
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+#include "parser.h"
+#include "hash.h"
+
+#define LEN_NEIGHBOUR_REQ 0
+#define LEN_NEIGHBOUR 18
+#define LEN_NETWORK_HASH 16
+#define LEN_NETWORK_STATE_REQ 0
+#define LEN_NODE_HASH 26
+#define LEN_NODE_STATE_REQ 8
+#define MIN_LEN_NODE_STATE 26
+#define MAX_LEN_NODE_STATE 218
+
+// 8 octets min (struct pointer 4 octets), 1024 octets max
+typedef struct packet {
+	unsigned char magic; // 95 (si autre, ignorer)
+	unsigned char version; // 1 (si autre, ignorer)
+	short length; // 1020 max
+	char *body;
+} packet;
+
+// 1 octet
+typedef struct pad1 {
+	unsigned char type;
+} pad1;
+
+// 2 octets min, 258 octets max (unsigned char 0 -> 255)
+typedef struct padn {
+	unsigned char type;
+	unsigned char length;
+	char mbz[256];
+} padn;
+
+// 2 octets
+typedef struct neighbour_req {
+	unsigned char type;
+	unsigned char length;
+} neighbour_req;
+
+// 20 octets
+typedef struct neighbour {
+	unsigned char type;
+	unsigned char length;
+	struct in6_addr ip;
+	short port;
+} neighbour;
+
+// 18 octets
+typedef struct network_hash {
+	unsigned char type;
+	unsigned char length;
+	char network_hash[16];
+} network_hash;
+
+// 2 octets
+typedef struct network_state_req {
+	unsigned char type;
+	unsigned char length;
+} network_state_req;
+
+// 28 octets
+typedef struct node_hash {
+	unsigned char type;
+	unsigned char length;
+	long node_id;
+	short seqno;
+	char node_hash[16];
+} node_hash;
+
+// 10 octets
+typedef struct node_state_req {
+	unsigned char type;
+	unsigned char length;
+	long node_id;
+} node_state_req;
+
+// 28 octets min, 220 octets max (data 0 -> 192)
+typedef struct node_state {
+	unsigned char type;
+	unsigned char length;
+	long node_id;
+	short seqno;
+	char node_hash[16];
+	char data[192];
+} node_state;
+
+// 2 octets min, 258 ocets max (unsigned char 0 -> 255)
+typedef struct warning {
+	unsigned char type;
+	unsigned char length;
+	char message[256];
+} warning;
+
+typedef union tlv {
+	pad1 *pad1;
+	padn *padn;
+	neighbour_req *neighbour_req;
+	neighbour *neighbour;
+	network_hash *network_hash;
+	network_state_req *network_state_req;
+	node_hash *node_hash;
+	node_state_req *node_state_req;
+	node_state *node_state;
+	warning *warning;
+} tlv;
+
+// build tlv from token
+int build_tlv(tlv *tlv, cmd_token token);
+
+// build specific tlv
+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_state_req(tlv *tlv);
+int build_node_hash(tlv *tlv, long node_id, short seqno, char *node_hash);
+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);
+
+#endif
diff --git a/src/énoncé.pdf b/src/énoncé.pdf
new file mode 100644
index 0000000..0d725fe
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