Merge remote-tracking branch 'ProjectTox/master'

1 files changed, 445 insertions, 361 deletions

diff --git a/core/DHT.c b/core/DHT.c
index 030c578e..857ac5e8 100644
--- a/core/DHT.c
+++ b/core/DHT.c
@@ -1,33 +1,28 @@
 /* DHT.c
-* 
-* An implementation of the DHT as seen in docs/DHT.txt
-* 
- 
-    Copyright (C) 2013 Tox project All Rights Reserved.
-
-    This file is part of Tox.
-
-    Tox is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    Tox is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with Tox.  If not, see <http://www.gnu.org/licenses/>.
-    
-*/
-
-
-
+ * 
+ * An implementation of the DHT as seen in docs/DHT.txt
+ *
+ *  Copyright (C) 2013 Tox project All Rights Reserved.
+ *
+ *  This file is part of Tox.
+ *
+ *  Tox is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Tox is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Tox.  If not, see <http://www.gnu.org/licenses/>.
+ *  
+ */
 
 #include "DHT.h"
 
-
 typedef struct
 {
     uint8_t client_id[CLIENT_ID_SIZE];
@@ -38,17 +33,24 @@ typedef struct
                            (for nodes in friends_list) or us (for nodes in close_clientlist) */
     uint32_t ret_timestamp;                       
 }Client_data;
+
 /* maximum number of clients stored per friend. */
 #define MAX_FRIEND_CLIENTS 8
+
 typedef struct
 {
     uint8_t client_id[CLIENT_ID_SIZE];
     Client_data client_list[MAX_FRIEND_CLIENTS];
     uint32_t lastgetnode; /* time at which the last get_nodes request was sent. */
     
+    /*Symetric NAT hole punching stuff*/
+    uint8_t hole_punching; /*0 if not hole punching, 1 if currently hole punching */
+    uint32_t punching_index;
+    uint32_t punching_timestamp;
+    uint64_t NATping_id;
+    uint32_t NATping_timestamp;
 }Friend;
 
-
 typedef struct
 {
     uint8_t client_id[CLIENT_ID_SIZE];
@@ -72,13 +74,11 @@ uint8_t self_secret_key[crypto_box_SECRETKEYBYTES];
 #define LCLIENT_LIST 32
 static Client_data close_clientlist[LCLIENT_LIST];
 
-
-
 static Friend * friends_list;
 static uint16_t num_friends;
 
 /* The list of ip ports along with the ping_id of what we sent them and a timestamp */
-#define LPING_ARRAY 128
+#define LPING_ARRAY 256
 
 static Pinged pings[LPING_ARRAY];
 
@@ -86,7 +86,6 @@ static Pinged pings[LPING_ARRAY];
 
 static Pinged send_nodes[LSEND_NODES_ARRAY];
 
-
 /* Compares client_id1 and client_id2 with client_id
    return 0 if both are same distance
    return 1 if client_id1 is closer
@@ -94,17 +93,12 @@ static Pinged send_nodes[LSEND_NODES_ARRAY];
 int id_closest(uint8_t * client_id, uint8_t * client_id1, uint8_t * client_id2) /* tested */
 {
     uint32_t i;
-    for(i = 0; i < CLIENT_ID_SIZE; ++i)
-    {
-        if(abs(client_id[i] ^ client_id1[i]) < abs(client_id[i] ^ client_id2[i]))
-        {
+    for(i = 0; i < CLIENT_ID_SIZE; ++i) {
+        if(abs(client_id[i] ^ client_id1[i]) < abs(client_id[i] ^ client_id2[i])) {
             return 1;
-        }
-        else if(abs(client_id[i] ^ client_id1[i]) > abs(client_id[i] ^ client_id2[i]))
-        {
+        } else if(abs(client_id[i] ^ client_id1[i]) > abs(client_id[i] ^ client_id2[i])) {
             return 2;
         }
-        
     }
     
     return 0;
@@ -121,17 +115,14 @@ int client_in_list(Client_data * list, uint32_t length, uint8_t * client_id, IP_
     uint32_t i;
     uint32_t temp_time = unix_time();
     
-    for(i = 0; i < length; ++i)
-    {
+    for(i = 0; i < length; ++i) {
         /*If ip_port is assigned to a different client_id replace it*/
         if(list[i].ip_port.ip.i == ip_port.ip.i &&
-        list[i].ip_port.port == ip_port.port)
-        {
+        list[i].ip_port.port == ip_port.port) {
             memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
         }
         
-        if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0)
-        {
+        if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
             /* Refresh the client timestamp. */
             list[i].timestamp = temp_time;
             list[i].ip_port.ip.i = ip_port.ip.i;
@@ -148,10 +139,8 @@ int client_in_list(Client_data * list, uint32_t length, uint8_t * client_id, IP_
 int client_in_nodelist(Node_format * list, uint32_t length, uint8_t * client_id)
 {
     uint32_t i;
-    for(i = 0; i < length; ++i)
-    {
-        if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0)
-        {
+    for(i = 0; i < length; ++i) {
+        if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
 
             return 1;
         }
@@ -160,14 +149,25 @@ int client_in_nodelist(Node_format * list, uint32_t length, uint8_t * client_id)
     
 }
 
-
+/*Return the friend number from the client_id
+ Return -1 if failure, number of friend if success*/
+static int friend_number(uint8_t * client_id)
+{
+    uint32_t i;
+    for(i = 0; i < num_friends; ++i) {
+        if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) /* Equal */
+        {
+            return i;
+        }
+    }
+    return -1;
+}
 
 /* the number of seconds for a non responsive node to become bad. */
-#define BAD_NODE_TIMEOUT 130
+#define BAD_NODE_TIMEOUT 70
 /* the max number of nodes to send with send nodes. */
 #define MAX_SENT_NODES 8
 
-
 /* Find MAX_SENT_NODES nodes closest to the client_id for the send nodes request:
    put them in the nodes_list and return how many were found.
    TODO: Make this function much more efficient. */
@@ -176,48 +176,35 @@ int get_close_nodes(uint8_t * client_id, Node_format * nodes_list)
     uint32_t i, j, k;
     int num_nodes=0;
     uint32_t temp_time = unix_time();
-    for(i = 0; i < LCLIENT_LIST; ++i)
-    {
+    for(i = 0; i < LCLIENT_LIST; ++i) {
         if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time && 
-        !client_in_nodelist(nodes_list, MAX_SENT_NODES,close_clientlist[i].client_id))
+        !client_in_nodelist(nodes_list, MAX_SENT_NODES,close_clientlist[i].client_id)) {
         /* if node is good and not already in list. */
-        {
-            if(num_nodes < MAX_SENT_NODES)
-            {
+            if(num_nodes < MAX_SENT_NODES) {
                     memcpy(nodes_list[num_nodes].client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE);
                     nodes_list[num_nodes].ip_port = close_clientlist[i].ip_port;
                     num_nodes++;
             }
-            else for(j = 0; j < MAX_SENT_NODES; ++j)
-            {
-                if(id_closest(client_id, nodes_list[j].client_id, close_clientlist[i].client_id) == 2)
-                {
+            else for(j = 0; j < MAX_SENT_NODES; ++j) {
+                if(id_closest(client_id, nodes_list[j].client_id, close_clientlist[i].client_id) == 2) {
                     memcpy(nodes_list[j].client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE);
                     nodes_list[j].ip_port = close_clientlist[i].ip_port;
                     break;
                 }
             }
-        }
-        
+        }    
     }
-    for(i = 0; i < num_friends; ++i)
-    {
-        for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-        {
+    for(i = 0; i < num_friends; ++i) {
+        for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
             if(friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time && 
-            !client_in_nodelist(nodes_list, MAX_SENT_NODES,friends_list[i].client_list[j].client_id))
+            !client_in_nodelist(nodes_list, MAX_SENT_NODES,friends_list[i].client_list[j].client_id)) {
             /* if node is good and not already in list. */
-            {
-                if(num_nodes < MAX_SENT_NODES)
-                {
+                if(num_nodes < MAX_SENT_NODES) {
                         memcpy(nodes_list[num_nodes].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
                         nodes_list[num_nodes].ip_port = friends_list[i].client_list[j].ip_port;
                         num_nodes++;
-                }
-                else for(k = 0; k < MAX_SENT_NODES; ++k)
-                {
-                    if(id_closest(client_id, nodes_list[k].client_id, friends_list[i].client_list[j].client_id) == 2)
-                    {
+                } else for(k = 0; k < MAX_SENT_NODES; ++k) {
+                    if(id_closest(client_id, nodes_list[k].client_id, friends_list[i].client_list[j].client_id) == 2) {
                         memcpy(nodes_list[k].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
                         nodes_list[k].ip_port = friends_list[i].client_list[j].ip_port;
                         break;
@@ -227,12 +214,9 @@ int get_close_nodes(uint8_t * client_id, Node_format * nodes_list)
         }        
     }
     
-    return num_nodes;
-    
+    return num_nodes;   
 }
 
-
-
 /* replace first bad (or empty) node with this one
    return 0 if successful
    return 1 if not (list contains no bad nodes) */
@@ -240,10 +224,8 @@ int replace_bad(Client_data * list, uint32_t length, uint8_t * client_id, IP_Por
 {
     uint32_t i;
     uint32_t temp_time = unix_time();
-    for(i = 0; i < length; ++i)
-    {
-        if(list[i].timestamp + BAD_NODE_TIMEOUT < temp_time) /* if node is bad. */
-        {
+    for(i = 0; i < length; ++i) {
+        if(list[i].timestamp + BAD_NODE_TIMEOUT < temp_time) /* if node is bad. */ {
             memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
             list[i].ip_port = ip_port;
             list[i].timestamp = temp_time;
@@ -263,10 +245,8 @@ int replace_good(Client_data * list, uint32_t length, uint8_t * client_id, IP_Po
     uint32_t i;
     uint32_t temp_time = unix_time();
     
-    for(i = 0; i < length; ++i)
-    {
-        if(id_closest(comp_client_id, list[i].client_id, client_id) == 2)
-        {
+    for(i = 0; i < length; ++i) {
+        if(id_closest(comp_client_id, list[i].client_id, client_id) == 2) {
             memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
             list[i].ip_port = ip_port;
             list[i].timestamp = temp_time;
@@ -286,23 +266,16 @@ void addto_lists(IP_Port ip_port, uint8_t * client_id)
     uint32_t i;
     
     /* NOTE: current behavior if there are two clients with the same id is to replace the first ip by the second. */
-    if(!client_in_list(close_clientlist, LCLIENT_LIST, client_id, ip_port))
-    {
+    if(!client_in_list(close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
          
-        if(replace_bad(close_clientlist, LCLIENT_LIST, client_id, ip_port))
-        {
+        if(replace_bad(close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
             /* if we can't replace bad nodes we try replacing good ones */
             replace_good(close_clientlist, LCLIENT_LIST, client_id, ip_port, self_public_key);
-        }
-        
+        }    
     }
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(!client_in_list(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port))
-        {
-            
-            if(replace_bad(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port))
-            {
+    for(i = 0; i < num_friends; ++i) {
+        if(!client_in_list(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port)) {  
+            if(replace_bad(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port)) {
                 /* if we can't replace bad nodes we try replacing good ones. */
                 replace_good(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port, friends_list[i].client_id);
             }
@@ -316,12 +289,9 @@ void returnedip_ports(IP_Port ip_port, uint8_t * client_id, uint8_t * nodeclient
 {
     uint32_t i, j;
     uint32_t temp_time = unix_time();
-    if(memcmp(client_id, self_public_key, CLIENT_ID_SIZE) == 0)
-    {
-        for(i = 0; i < LCLIENT_LIST; ++i)
-        {
-            if(memcmp(nodeclient_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0)
-            {
+    if(memcmp(client_id, self_public_key, CLIENT_ID_SIZE) == 0) {
+        for(i = 0; i < LCLIENT_LIST; ++i) {
+            if(memcmp(nodeclient_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0) {
                 close_clientlist[i].ret_ip_port = ip_port;
                 close_clientlist[i].ret_timestamp = temp_time;
                 return;
@@ -329,14 +299,10 @@ void returnedip_ports(IP_Port ip_port, uint8_t * client_id, uint8_t * nodeclient
         }
     }
     else
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(memcmp(client_id, friends_list[i].client_id, CLIENT_ID_SIZE) == 0)
-        {
-            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-            {
-                if(memcmp(nodeclient_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE) == 0)
-                {
+    for(i = 0; i < num_friends; ++i) {
+        if(memcmp(client_id, friends_list[i].client_id, CLIENT_ID_SIZE) == 0) {
+            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
+                if(memcmp(nodeclient_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE) == 0) {
                     friends_list[i].client_list[j].ret_ip_port = ip_port;
                     friends_list[i].client_list[j].ret_timestamp = temp_time;
                     return;
@@ -348,6 +314,7 @@ void returnedip_ports(IP_Port ip_port, uint8_t * client_id, uint8_t * nodeclient
 
 /* ping timeout in seconds */
 #define PING_TIMEOUT 5
+
 /* check if we are currently pinging an ip_port and/or a ping_id
    variables with values of zero will not be checked.
    if we are already, return 1
@@ -359,28 +326,22 @@ int is_pinging(IP_Port ip_port, uint64_t ping_id)
     uint8_t pinging;
     uint32_t temp_time = unix_time();
 
-    for(i = 0; i < LPING_ARRAY; ++i )
-    {
-        if((pings[i].timestamp + PING_TIMEOUT) > temp_time)
-        {
+    for(i = 0; i < LPING_ARRAY; ++i ) {
+        if((pings[i].timestamp + PING_TIMEOUT) > temp_time) {
             pinging = 0;
-            if(ip_port.ip.i != 0)
-            {
+            if(ip_port.ip.i != 0) {
                 if(pings[i].ip_port.ip.i == ip_port.ip.i &&
-                pings[i].ip_port.port == ip_port.port)
-                {
+                pings[i].ip_port.port == ip_port.port) {
                         ++pinging;
                 }
             }
-            if(ping_id != 0)
-            {
+            if(ping_id != 0) {
                 if(pings[i].ping_id == ping_id)
                 {
                         ++pinging;
                 }
             }
-            if(pinging == (ping_id != 0) + (ip_port.ip.i != 0))
-            {
+            if(pinging == (ping_id != 0) + (ip_port.ip.i != 0)) {
                     return 1;
             }
             
@@ -391,7 +352,6 @@ int is_pinging(IP_Port ip_port, uint64_t ping_id)
     
 }
 
-
 /* Same as last function but for get_node requests. */
 int is_gettingnodes(IP_Port ip_port, uint64_t ping_id)
 {
@@ -399,28 +359,21 @@ int is_gettingnodes(IP_Port ip_port, uint64_t ping_id)
     uint8_t pinging;
     uint32_t temp_time = unix_time();
 
-    for(i = 0; i < LSEND_NODES_ARRAY; ++i )
-    {
-        if((send_nodes[i].timestamp + PING_TIMEOUT) > temp_time)
-        {
+    for(i = 0; i < LSEND_NODES_ARRAY; ++i ) {
+        if((send_nodes[i].timestamp + PING_TIMEOUT) > temp_time) {
             pinging = 0;
-            if(ip_port.ip.i != 0)
-            {
+            if(ip_port.ip.i != 0) {
                 if(send_nodes[i].ip_port.ip.i == ip_port.ip.i &&
-                send_nodes[i].ip_port.port == ip_port.port)
-                {
+                send_nodes[i].ip_port.port == ip_port.port) {
                         ++pinging;
                 }
             }
-            if(ping_id != 0)
-            {
-                if(send_nodes[i].ping_id == ping_id)
-                {
+            if(ping_id != 0) {
+                if(send_nodes[i].ping_id == ping_id) {
                         ++pinging;
                 }
             }
-            if(pinging == (ping_id != 0) + (ip_port.ip.i != 0))
-            {
+            if(pinging == (ping_id != 0) + (ip_port.ip.i != 0)) {
                     return 1;
             }
             
@@ -431,7 +384,6 @@ int is_gettingnodes(IP_Port ip_port, uint64_t ping_id)
     
 }
 
-
 /* Add a new ping request to the list of ping requests
    returns the ping_id to put in the ping request
    returns 0 if problem.
@@ -442,12 +394,9 @@ uint64_t add_pinging(IP_Port ip_port)
     uint64_t ping_id = ((uint64_t)random_int() << 32) + random_int();
     uint32_t temp_time = unix_time();
     
-    for(i = 0; i < PING_TIMEOUT; ++i )
-    {
-        for(j = 0; j < LPING_ARRAY; ++j )
-        {
-            if((pings[j].timestamp + PING_TIMEOUT - i) < temp_time)
-            {
+    for(i = 0; i < PING_TIMEOUT; ++i ) {
+        for(j = 0; j < LPING_ARRAY; ++j ) {
+            if((pings[j].timestamp + PING_TIMEOUT - i) < temp_time) {
                     pings[j].timestamp = temp_time;
                     pings[j].ip_port = ip_port;
                     pings[j].ping_id = ping_id;
@@ -466,12 +415,9 @@ uint64_t add_gettingnodes(IP_Port ip_port)
     uint64_t ping_id = ((uint64_t)random_int() << 32) + random_int();
     uint32_t temp_time = unix_time();
     
-    for(i = 0; i < PING_TIMEOUT; ++i )
-    {
-        for(j = 0; j < LSEND_NODES_ARRAY; ++j )
-        {
-            if((send_nodes[j].timestamp + PING_TIMEOUT - i) < temp_time)
-            {
+    for(i = 0; i < PING_TIMEOUT; ++i ) {
+        for(j = 0; j < LSEND_NODES_ARRAY; ++j ) {
+            if((send_nodes[j].timestamp + PING_TIMEOUT - i) < temp_time) {
                     send_nodes[j].timestamp = temp_time;
                     send_nodes[j].ip_port = ip_port;
                     send_nodes[j].ping_id = ping_id;
@@ -483,25 +429,20 @@ uint64_t add_gettingnodes(IP_Port ip_port)
     
 }
 
-
-
 /* send a ping request
    Ping request only works if none has been sent to that ip/port in the last 5 seconds. */
 static int pingreq(IP_Port ip_port, uint8_t * public_key)
 {
-    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */
-    {
+    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */ {
         return 1;
     }
     
-    if(is_pinging(ip_port, 0))
-    {
+    if(is_pinging(ip_port, 0)) {
         return 1;
     }
     
     uint64_t ping_id = add_pinging(ip_port);
-    if(ping_id == 0)
-    {
+    if(ping_id == 0) {
         return 1;
     }
     
@@ -511,8 +452,7 @@ static int pingreq(IP_Port ip_port, uint8_t * public_key)
     random_nonce(nonce);
     
     int len = encrypt_data(public_key, self_secret_key, nonce, (uint8_t *)&ping_id, sizeof(ping_id), encrypt);
-    if(len != sizeof(ping_id) + ENCRYPTION_PADDING)
-    {
+    if(len != sizeof(ping_id) + ENCRYPTION_PADDING) {
         return -1;
     }
     data[0] = 0;
@@ -524,12 +464,11 @@ static int pingreq(IP_Port ip_port, uint8_t * public_key)
     
 }
 
-
 /* send a ping response */
 static int pingres(IP_Port ip_port, uint8_t * public_key, uint64_t ping_id)
 {
-    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */
-    {
+     /* check if packet is gonna be sent to ourself */
+    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) {
         return 1;
     }
     
@@ -539,8 +478,7 @@ static int pingres(IP_Port ip_port, uint8_t * public_key, uint64_t ping_id)
     random_nonce(nonce);
     
     int len = encrypt_data(public_key, self_secret_key, nonce, (uint8_t *)&ping_id, sizeof(ping_id), encrypt);
-    if(len != sizeof(ping_id) + ENCRYPTION_PADDING)
-    {
+    if(len != sizeof(ping_id) + ENCRYPTION_PADDING) {
         return -1;
     }
     data[0] = 1;
@@ -555,20 +493,18 @@ static int pingres(IP_Port ip_port, uint8_t * public_key, uint64_t ping_id)
 /* send a getnodes request */
 static int getnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id)
 {
-    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */
-    {
+    /* check if packet is gonna be sent to ourself */
+    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) {
         return 1;
     }
     
-    if(is_gettingnodes(ip_port, 0))
-    {
+    if(is_gettingnodes(ip_port, 0)) {
         return 1;
     }
     
     uint64_t ping_id = add_gettingnodes(ip_port);
     
-    if(ping_id == 0)
-    {
+    if(ping_id == 0) {
         return 1;
     }
     
@@ -583,8 +519,7 @@ static int getnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id)
     
     int len = encrypt_data(public_key, self_secret_key, nonce, plain, sizeof(ping_id) + CLIENT_ID_SIZE, encrypt);
     
-    if(len != sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING)
-    {
+    if(len != sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING) {
         return -1;
     }
     data[0] = 2;
@@ -595,12 +530,10 @@ static int getnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id)
     
 }
 
-
 /* send a send nodes response */
 static int sendnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id, uint64_t ping_id)
 {
-    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */
-    {
+    if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */ {
         return 1;
     }
     
@@ -610,8 +543,7 @@ static int sendnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id,
     Node_format nodes_list[MAX_SENT_NODES];
     int num_nodes = get_close_nodes(client_id, nodes_list);
     
-    if(num_nodes == 0)
-    {
+    if(num_nodes == 0) {
         return 0;
     }
     
@@ -626,8 +558,7 @@ static int sendnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id,
     int len = encrypt_data(public_key, self_secret_key, nonce, plain, 
                                        sizeof(ping_id) + num_nodes * sizeof(Node_format), encrypt);
     
-    if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format) + ENCRYPTION_PADDING)
-    {
+    if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format) + ENCRYPTION_PADDING) {
         return -1;
     }
     
@@ -640,20 +571,17 @@ static int sendnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id,
    
 }
 
-
-
 /* Packet handling functions
    One to handle each types of packets we receive
    return 0 if handled correctly, 1 if packet is bad. */
 int handle_pingreq(uint8_t * packet, uint32_t length, IP_Port source)
 {
     uint64_t ping_id;
-    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING)
-    {
+    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING) {
         return 1;
     }
-    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is from ourself. */
-    {
+        /* check if packet is from ourself. */
+    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0)  {
         return 1;
     }
     
@@ -662,8 +590,7 @@ int handle_pingreq(uint8_t * packet, uint32_t length, IP_Port source)
     int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE, 
                                        packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, 
                                        sizeof(ping_id) + ENCRYPTION_PADDING, (uint8_t *)&ping_id);
-    if(len != sizeof(ping_id))
-    {
+    if(len != sizeof(ping_id)) {
         return 1;
     }
 
@@ -679,12 +606,10 @@ int handle_pingreq(uint8_t * packet, uint32_t length, IP_Port source)
 int handle_pingres(uint8_t * packet, uint32_t length, IP_Port source)
 {
     uint64_t ping_id;
-    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING)
-    {
+    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING) {
         return 1;
     }
-    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is from ourself. */
-    {
+    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is from ourself. */ {
         return 1;
     }
     
@@ -693,13 +618,11 @@ int handle_pingres(uint8_t * packet, uint32_t length, IP_Port source)
     int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE, 
                                        packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, 
                                        sizeof(ping_id) + ENCRYPTION_PADDING, (uint8_t *)&ping_id);
-    if(len != sizeof(ping_id))
-    {
+    if(len != sizeof(ping_id)) {
         return 1;
     }
     
-    if(is_pinging(source, ping_id))
-    {
+    if(is_pinging(source, ping_id)) {
         addto_lists(source, packet + 1);
         return 0;
     }
@@ -710,12 +633,11 @@ int handle_pingres(uint8_t * packet, uint32_t length, IP_Port source)
 int handle_getnodes(uint8_t * packet, uint32_t length, IP_Port source)
 {
     uint64_t ping_id;
-    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING)
-    {
+    if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING) {
         return 1;
     }
-    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is from ourself. */
-    {
+        /* check if packet is from ourself. */
+    if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) {
         return 1;
     }
     
@@ -725,8 +647,7 @@ int handle_getnodes(uint8_t * packet, uint32_t length, IP_Port source)
                                        packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, 
                                        sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING, plain);
     
-    if(len != sizeof(ping_id) + CLIENT_ID_SIZE)
-    {
+    if(len != sizeof(ping_id) + CLIENT_ID_SIZE) {
         return 1;
     }
     
@@ -748,8 +669,7 @@ int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
     (length - (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) 
                  + ENCRYPTION_PADDING)) % (sizeof(Node_format)) != 0 ||
      length < 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) 
-                                 + sizeof(Node_format) + ENCRYPTION_PADDING)
-    {
+                                 + sizeof(Node_format) + ENCRYPTION_PADDING) {
         return 1;
     } 
     uint32_t num_nodes = (length - (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES 
@@ -762,14 +682,12 @@ int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
                                        sizeof(ping_id) + num_nodes * sizeof(Node_format) + ENCRYPTION_PADDING, plain);
     
     
-    if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format))
-    {
+    if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format)) {
         return 1;
     }
         
     memcpy(&ping_id, plain, sizeof(ping_id));
-    if(!is_gettingnodes(source, ping_id))
-    {
+    if(!is_gettingnodes(source, ping_id)) {
         return 1;
     }
     
@@ -779,8 +697,7 @@ int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
     addto_lists(source, packet + 1);
     
     uint32_t i;
-    for(i = 0; i < num_nodes; ++i)
-    {
+    for(i = 0; i < num_nodes; ++i)  {
         pingreq(nodes_list[i].ip_port, nodes_list[i].client_id);
         returnedip_ports(nodes_list[i].ip_port, nodes_list[i].client_id, packet + 1);
     }
@@ -793,44 +710,36 @@ int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
 int DHT_addfriend(uint8_t * client_id)
 {
     Friend * temp;
-    if(num_friends == 0)
-    {
+    if(num_friends == 0) {
         temp = malloc(sizeof(Friend));
-    }
-    else
-    {
+    } else {
         temp = realloc(friends_list, sizeof(Friend) * (num_friends + 1));
     }
-    if(temp == NULL)
-    {
+    if(temp == NULL) {
         return 1;
     }
     
     friends_list = temp;
     memset(&friends_list[num_friends], 0, sizeof(Friend));
     memcpy(friends_list[num_friends].client_id, client_id, CLIENT_ID_SIZE);
+    friends_list[num_friends].NATping_id = ((uint64_t)random_int() << 32) + random_int();
     ++num_friends;
     return 0;
 }
 
-
-
 int DHT_delfriend(uint8_t * client_id)
 {
     uint32_t i;
     Friend * temp;
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) /* Equal */
-        {
+    for(i = 0; i < num_friends; ++i) {
+            /* Equal */ 
+        if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0){
             --num_friends;
-            if(num_friends != i)
-            {
+            if(num_friends != i) {
                 memcpy(friends_list[i].client_id, friends_list[num_friends].client_id, CLIENT_ID_SIZE);
             }
             temp = realloc(friends_list, sizeof(Friend) * (num_friends));
-            if(temp != NULL)
-            {
+            if(temp != NULL) {
                 friends_list = temp;
             }
             return 0;
@@ -839,61 +748,27 @@ int DHT_delfriend(uint8_t * client_id)
     return 1;
 }
 
-
-
-
 /* TODO: Optimize this. */
 IP_Port DHT_getfriendip(uint8_t * client_id)
 {
     uint32_t i, j;
     IP_Port empty = {{{0}}, 0};
     uint32_t temp_time = unix_time();
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) /* Equal */
-        {
-            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-            {
+    for(i = 0; i < num_friends; ++i) {
+             /* Equal */
+        if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
+            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
                 if(memcmp(friends_list[i].client_list[j].client_id, client_id, CLIENT_ID_SIZE) == 0 && 
-                 friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time)
-                {
+                 friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time) {
                     return friends_list[i].client_list[j].ip_port;
-                }
-                
-            }
-                
+                }   
+            }        
             return empty;
         }
     }
     empty.ip.i = 1;
     return empty;
     
-}    
-
-
-
-int DHT_handlepacket(uint8_t * packet, uint32_t length, IP_Port source)
-{
-    switch (packet[0]) {
-    case 0:
-        return handle_pingreq(packet, length, source);   
-        
-    case 1:
-        return handle_pingres(packet, length, source); 
-        
-    case 2:
-        return handle_getnodes(packet, length, source); 
-        
-    case 3:
-        return handle_sendnodes(packet, length, source);
-        
-    default: 
-        return 1;
-        
-    }
-
-    return 0;
-
 }
 
 /* The timeout after which a node is discarded completely. */
@@ -907,8 +782,6 @@ int DHT_handlepacket(uint8_t * packet, uint32_t length, IP_Port source)
 
 /* Ping each client in the "friends" list every 60 seconds.
    Send a get nodes request every 20 seconds to a random good node for each "friend" in our "friends" list. */
-
-
 void doDHTFriends()
 {
     uint32_t i, j;
@@ -916,27 +789,21 @@ void doDHTFriends()
     uint32_t rand_node;
     uint32_t index[MAX_FRIEND_CLIENTS];
     
-    for(i = 0; i < num_friends; ++i)
-    {
+    for(i = 0; i < num_friends; ++i) {
         uint32_t num_nodes = 0;
-        for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-        {
-            if(friends_list[i].client_list[j].timestamp + Kill_NODE_TIMEOUT > temp_time) /* if node is not dead. */
-            {
-                if((friends_list[i].client_list[j].last_pinged + PING_INTERVAL) <= temp_time)
-                {
+        for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
+            if(friends_list[i].client_list[j].timestamp + Kill_NODE_TIMEOUT > temp_time) /* if node is not dead. */ {
+                if((friends_list[i].client_list[j].last_pinged + PING_INTERVAL) <= temp_time) {
                     pingreq(friends_list[i].client_list[j].ip_port, friends_list[i].client_list[j].client_id);
                     friends_list[i].client_list[j].last_pinged = temp_time;
                 }
-                if(friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time) /* if node is good. */
-                {
+                if(friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time) /* if node is good. */ {
                     index[num_nodes] = j;
                     ++num_nodes;
                 }
             }
         }
-        if(friends_list[i].lastgetnode + GET_NODE_INTERVAL <= temp_time && num_nodes != 0)
-        {
+        if(friends_list[i].lastgetnode + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
             rand_node = rand() % num_nodes;
             getnodes(friends_list[i].client_list[index[rand_node]].ip_port, 
                      friends_list[i].client_list[index[rand_node]].client_id, 
@@ -958,66 +825,77 @@ void doClose() /* tested */
     uint32_t rand_node;
     uint32_t index[LCLIENT_LIST];
     
-    for(i = 0; i < LCLIENT_LIST; ++i)
-    {
-        if(close_clientlist[i].timestamp + Kill_NODE_TIMEOUT > temp_time) /* if node is not dead. */
-        {
+    for(i = 0; i < LCLIENT_LIST; ++i) {
+            /* if node is not dead. */
+        if(close_clientlist[i].timestamp + Kill_NODE_TIMEOUT > temp_time) {
             if((close_clientlist[i].last_pinged + PING_INTERVAL) <= temp_time)
             {
                 pingreq(close_clientlist[i].ip_port, close_clientlist[i].client_id);
                 close_clientlist[i].last_pinged = temp_time;
             }
-            if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time) /* if node is good. */
-            {
+                        /* if node is good. */
+            if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time) {
                 index[num_nodes] = i;
                 ++num_nodes;
             }
         }   
     }
     
-    if(close_lastgetnodes + GET_NODE_INTERVAL <= temp_time && num_nodes != 0)
-    {
+    if(close_lastgetnodes + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
         rand_node = rand() % num_nodes;
         getnodes(close_clientlist[index[rand_node]].ip_port, 
                  close_clientlist[index[rand_node]].client_id, 
                  self_public_key);
         close_lastgetnodes = temp_time;
     }
-    
-}
-
-
-
-void doDHT()
-{
-    doClose();
-    doDHTFriends();
 }
 
-
-
 void DHT_bootstrap(IP_Port ip_port, uint8_t * public_key)
 {
     getnodes(ip_port, public_key, self_public_key);   
 }
 
-
-
 /* send the given packet to node with client_id
    returns -1 if failure */
 int route_packet(uint8_t * client_id, uint8_t * packet, uint32_t length)
 {
     uint32_t i;
-    for(i = 0; i < LCLIENT_LIST; ++i)
-    {
-        if(memcmp(client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0)
-        {
+    for(i = 0; i < LCLIENT_LIST; ++i) {
+        if(memcmp(client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0) {
             return sendpacket(close_clientlist[i].ip_port, packet, length);
         }
     }
     return -1;
 }
 
+/* Puts all the different ips returned by the nodes for a friend_num into array ip_portlist 
+   ip_portlist must be at least MAX_FRIEND_CLIENTS big
+   returns the number of ips returned
+   return 0 if we are connected to friend or if no ips were found.
+   returns -1 if no such friend*/
+static int friend_iplist(IP_Port * ip_portlist, uint16_t friend_num)
+{
+    int num_ips = 0;
+    uint32_t i;
+    uint32_t temp_time = unix_time();
+    if(friend_num >= num_friends) {
+        return -1;
+    }
+    for(i = 0; i < MAX_FRIEND_CLIENTS; ++i)
+    {
+            /*If ip is not zero and node is good */
+        if(friends_list[friend_num].client_list[i].ret_ip_port.ip.i != 0 && 
+            friends_list[friend_num].client_list[i].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
+            if(memcmp(friends_list[friend_num].client_list[i].client_id, friends_list[friend_num].client_id, CLIENT_ID_SIZE) == 0 ) {
+                return 0;
+            }
+            ip_portlist[num_ips] = friends_list[friend_num].client_list[i].ret_ip_port;
+            ++num_ips;
+        }
+    }
+    return num_ips;
+}
+
 /* Send the following packet to everyone who tells us they are connected to friend_id
    returns the number of nodes it sent the packet to */
 int route_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
@@ -1025,18 +903,14 @@ int route_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
     uint32_t i, j;
     uint32_t sent = 0;
     uint32_t temp_time = unix_time();
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0) /* Equal */
-        {
-            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-            {
+    for(i = 0; i < num_friends; ++i) {
+            /* Equal */
+        if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0)  {
+            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
+                             /*If ip is not zero and node is good */
                 if(friends_list[i].client_list[j].ret_ip_port.ip.i != 0 && 
-                   friends_list[i].client_list[j].ret_timestamp + BAD_NODE_TIMEOUT > temp_time)
-                   /*If ip is not zero and node is good */
-                {
-                    if(sendpacket(friends_list[i].client_list[j].ip_port, packet, length) == length)
-                    {
+                   friends_list[i].client_list[j].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
+                    if(sendpacket(friends_list[i].client_list[j].ip_port, packet, length) == length) {
                         ++sent;
                     }
                 }
@@ -1047,34 +921,255 @@ int route_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
     return 0;
 }
 
+/* Send the following packet to one random person who tells us they are connected to friend_id
+   returns the number of nodes it sent the packet to */
+int routeone_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
+{
+    int num = friend_number(friend_id);
+    if(num == -1) {
+        return 0;
+    }
+    
+    IP_Port ip_list[MAX_FRIEND_CLIENTS];
+    int n = 0;
+    uint32_t i;
+    uint32_t temp_time = unix_time();
+    for(i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
+            /*If ip is not zero and node is good */
+        if(friends_list[num].client_list[i].ret_ip_port.ip.i != 0 && 
+            friends_list[num].client_list[i].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
+            ip_list[n] = friends_list[num].client_list[i].ip_port;
+            ++n;
+        }
+    }
+    if(n < 1) {
+        return 0;
+    }
+    if(sendpacket(ip_list[rand() % n], packet, length) == length) {
+        return 1;
+    }
+    return 0;
+}
+
 /* Puts all the different ips returned by the nodes for a friend_id into array ip_portlist 
    ip_portlist must be at least MAX_FRIEND_CLIENTS big
    returns the number of ips returned
+   return 0 if we are connected to friend or if no ips were found.
    returns -1 if no such friend*/
 int friend_ips(IP_Port * ip_portlist, uint8_t * friend_id)
 {
-    int num_ips = 0;
+
+    uint32_t i;
+    for(i = 0; i < num_friends; ++i) {
+            /* Equal */
+        if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0) {
+            return friend_iplist(ip_portlist, i);
+        }
+    }
+    return -1;
+}
+
+/*BEGINNING OF NAT PUNCHING FUNCTIONS*/
+
+int send_NATping(uint8_t * public_key, uint64_t ping_id, uint8_t type)
+{
+    uint8_t data[sizeof(uint64_t) + 1];
+    data[0] = type;
+    memcpy(data + 1, &ping_id, sizeof(uint64_t));
+    
+    uint8_t packet[MAX_DATA_SIZE];
+    int len = create_request(packet, public_key, data, sizeof(uint64_t) + 1, 254); /* 254 is NAT ping request packet id */
+    if(len == -1) {
+        return -1;
+    }
+    int num = 0;
+    if(type == 0) {
+        num = route_tofriend(public_key, packet, len);/*If packet is request use many people to route it*/
+    }
+    else if(type == 1) {
+        num = routeone_tofriend(public_key, packet, len);/*If packet is response use only one person to route it*/
+    }
+    if(num == 0) {
+        return -1;
+    }
+    return num;
+}
+
+/* Handle a recieved ping request for */
+int handle_NATping(uint8_t * packet, uint32_t length, IP_Port source)
+{
+    if(length <= crypto_box_PUBLICKEYBYTES * 2 + crypto_box_NONCEBYTES + 1 + ENCRYPTION_PADDING &&
+    length > MAX_DATA_SIZE + ENCRYPTION_PADDING) {
+        return 1;
+    }
+        /* check if request is for us. */
+    if(memcmp(packet + 1, self_public_key, crypto_box_PUBLICKEYBYTES) == 0) {
+        uint8_t public_key[crypto_box_PUBLICKEYBYTES];
+        uint8_t data[MAX_DATA_SIZE];
+        int len = handle_request(public_key, data, packet, length);
+        if(len != sizeof(uint64_t) + 1) {
+            return 1;
+        }
+        uint64_t ping_id;
+        memcpy(&ping_id, data + 1, sizeof(uint64_t));
+        
+        int friendnumber = friend_number(public_key);
+        if(friendnumber == -1) {
+            return 1;
+        }
+        
+        if(data[0] == 0) {
+            send_NATping(public_key, ping_id, 1);/*1 is reply*/
+            return 0;
+        } else if (data[0] == 1) {
+            if(friends_list[friendnumber].NATping_id == ping_id)
+            {
+                friends_list[friendnumber].NATping_id = ((uint64_t)random_int() << 32) + random_int();
+                friends_list[friendnumber].hole_punching = 1;
+                return 0;
+            }
+        }
+        return 1;
+    }
+        /* if request is not for us, try routing it. */
+    else {
+        if(route_packet(packet + 1, packet, length) == length) {
+            return 0;
+        }
+    }
+    return 0;
+}
+
+/*Get the most common ip in the ip_portlist
+  Only return ip if it appears in list min_num or more
+  len must not be bigger than MAX_FRIEND_CLIENTS
+  return ip of 0 if failure */
+static IP NAT_commonip(IP_Port * ip_portlist, uint16_t len, uint16_t min_num)
+{
+    IP zero = {{0}};
+    if(len > MAX_FRIEND_CLIENTS) {
+        return zero;
+    }
+    
     uint32_t i, j;
+    uint16_t numbers[MAX_FRIEND_CLIENTS] = {0};
+    for(i = 0; i < len; ++i) {
+        for(j = 0; j < len; ++j) {
+            if(ip_portlist[i].ip.i == ip_portlist[j].ip.i) {
+                ++numbers[i];
+            }
+        }
+        if(numbers[i] >= min_num) {
+            return ip_portlist[i].ip;
+        }
+    }
+    return zero;
+}
+
+/*Return all the ports for one ip in a list
+  portlist must be at least len long
+  where len is the length of ip_portlist
+  returns the number of ports and puts the list of ports in portlist*/
+static uint16_t NAT_getports(uint16_t * portlist, IP_Port * ip_portlist, uint16_t len, IP ip)
+{
+    uint32_t i;
+    uint16_t num = 0;
+    for(i = 0; i < len; ++i) {
+        if(ip_portlist[i].ip.i == ip.i) {
+            portlist[num] = ntohs(ip_portlist[i].port);
+            ++num;
+        }
+    }
+    return num;
+}
+
+#define MAX_PUNCHING_PORTS 32
+
+static void punch_holes(IP ip, uint16_t * port_list, uint16_t numports, uint16_t friend_num)
+{
+    if(numports > MAX_FRIEND_CLIENTS || numports == 0) {
+        return;
+    }
+    uint32_t i;
+    uint32_t top = friends_list[friend_num].punching_index + MAX_PUNCHING_PORTS;
+    for(i = friends_list[friend_num].punching_index; i != top; i++) {
+        /*TODO: improve port guessing algorithm*/
+        uint16_t port = port_list[(i/2) % numports] + (i/(2*numports))*((i % 2) ? -1 : 1);
+        IP_Port pinging = {ip, htons(port)};
+        pingreq(pinging, friends_list[friend_num].client_id);
+    }
+    friends_list[friend_num].punching_index = i;
+}
+
+/*Interval in seconds between punching attempts*/
+#define PUNCH_INTERVAL 10
+
+static void doNAT()
+{
+    uint32_t i;
     uint32_t temp_time = unix_time();
-    for(i = 0; i < num_friends; ++i)
-    {
-        if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0) /* Equal */
-        {
-            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-            {
-                if(friends_list[i].client_list[j].ret_ip_port.ip.i != 0 && 
-                   friends_list[i].client_list[j].ret_timestamp + BAD_NODE_TIMEOUT > temp_time)
-                   /*If ip is not zero and node is good */
-                {
-                    ip_portlist[num_ips] = friends_list[i].client_list[j].ret_ip_port;
-                    ++num_ips;
-                }
+    for(i = 0; i < num_friends; ++i) {
+        IP_Port ip_list[MAX_FRIEND_CLIENTS];
+        int num = friend_iplist(ip_list, i);
+        /*If we are connected to friend or if friend is not online don't try to hole punch with him*/
+        if(num < MAX_FRIEND_CLIENTS/2) {
+            continue;
+        }
+        if(friends_list[i].hole_punching != 1) {
+            if(friends_list[i].NATping_timestamp + PUNCH_INTERVAL < temp_time) {
+                send_NATping(friends_list[i].client_id, friends_list[i].NATping_id, 0); /*0 is request*/
+                friends_list[i].NATping_timestamp = temp_time;
             }
-            return num_ips;
         }
+        else if(friends_list[i].punching_timestamp + PUNCH_INTERVAL < temp_time) {
+            IP ip = NAT_commonip(ip_list, num, MAX_FRIEND_CLIENTS/2);
+            if(ip.i == 0) {
+                continue;
+            }
+            uint16_t port_list[MAX_FRIEND_CLIENTS];
+            uint16_t numports = NAT_getports(port_list, ip_list, num, ip);
+            punch_holes(ip, port_list, numports, i);
+
+            friends_list[i].punching_timestamp = temp_time;
+            friends_list[i].hole_punching = 0;
+        }
+    }
+}
+
+/*END OF NAT PUNCHING FUNCTIONS*/
+
+int DHT_handlepacket(uint8_t * packet, uint32_t length, IP_Port source)
+{
+    switch (packet[0]) {
+    case 0:
+        return handle_pingreq(packet, length, source);   
+        
+    case 1:
+        return handle_pingres(packet, length, source); 
+        
+    case 2:
+        return handle_getnodes(packet, length, source); 
+        
+    case 3:
+        return handle_sendnodes(packet, length, source);
+        
+    case 254:
+        return handle_NATping(packet, length, source);
+        
+    default: 
+        return 1;
         
     }
+
     return 0;
+
+}
+
+void doDHT()
+{
+    doClose();
+    doDHTFriends();
+    doNAT();
 }
 
 /* get the size of the DHT (for saving) */
@@ -1095,12 +1190,10 @@ void DHT_save(uint8_t * data)
    return 0 if success */
 int DHT_load(uint8_t * data, uint32_t size)
 {
-    if(size < sizeof(close_clientlist))
-    {
+    if(size < sizeof(close_clientlist)) {
         return -1;
     }
-    if((size - sizeof(close_clientlist)) % sizeof(Friend) != 0)
-    {
+    if((size - sizeof(close_clientlist)) % sizeof(Friend) != 0) {
         return -1;
     }
     uint32_t i, j;
@@ -1109,17 +1202,13 @@ int DHT_load(uint8_t * data, uint32_t size)
     
     temp = (size - sizeof(close_clientlist))/sizeof(Friend);
     
-    if(temp != 0)
-    {
+    if(temp != 0) {
         Friend * tempfriends_list = (Friend *)(data + sizeof(close_clientlist));
 
-        for(i = 0; i < temp; ++i)
-        {
+        for(i = 0; i < temp; ++i) {
             DHT_addfriend(tempfriends_list[i].client_id);
-            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j)
-            {
-                if(tempfriends_list[i].client_list[j].timestamp != 0)
-                {                
+            for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
+                if(tempfriends_list[i].client_list[j].timestamp != 0) {                
                     getnodes(tempfriends_list[i].client_list[j].ip_port, 
                              tempfriends_list[i].client_list[j].client_id, tempfriends_list[i].client_id);
                 }
@@ -1128,10 +1217,8 @@ int DHT_load(uint8_t * data, uint32_t size)
     }
     Client_data * tempclose_clientlist = (Client_data *)data;
 
-    for(i = 0; i < LCLIENT_LIST; ++i)
-    {
-        if(tempclose_clientlist[i].timestamp != 0)
-        {
+    for(i = 0; i < LCLIENT_LIST; ++i) {
+        if(tempclose_clientlist[i].timestamp != 0) {
             DHT_bootstrap(tempclose_clientlist[i].ip_port, tempclose_clientlist[i].client_id);
         }
     }
@@ -1144,13 +1231,10 @@ int DHT_isconnected()
 {
     uint32_t i;
     uint32_t temp_time = unix_time();
-    for(i = 0; i < LCLIENT_LIST; ++i)
-    {
-        if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time)
-        {
+    for(i = 0; i < LCLIENT_LIST; ++i) {
+        if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time) {
             return 1;
         }
     }
     return 0;
-}
-
+}
\ No newline at end of file