DHT almost done, started testing. Fixed ADDR compiling problem. No more warnings with GCC and clang.

core/DHT.c

@@ -7,8 +7,7 @@
 //Function to send packet(data) of length length to ip_port
 int sendpacket(IP_Port ip_port, char * data, uint32_t length)
 {
-    ADDR addr = {.family = AF_INET, .ip = ip_port.ip, .port = ip_port.port};
+    ADDR addr = {AF_INET, ip_port.port, ip_port.ip}; 
-    
     return sendto(sock, data, length, 0, (struct sockaddr *)&addr, sizeof(addr));
 }
 
@@ -71,7 +70,7 @@ int client_in_list(Client_data * list, uint32_t length, char * client_id)
                 break;
             }
         }
-        if((j - 1) == CLIENT_ID_SIZE)
+        if(j == CLIENT_ID_SIZE)
         {
             //Refresh the client timestamp.
             list[i].timestamp = unix_time();
@@ -81,7 +80,7 @@ int client_in_list(Client_data * list, uint32_t length, char * client_id)
     return 0;
 }
 
-//check if client with client_id is already in knode format list of length length.
+//check if client with client_id is already in node format list of length length.
 //return True(1) or False(0)
 int client_in_nodelist(Node_format * list, uint32_t length, char * client_id)
 {
@@ -96,7 +95,7 @@ int client_in_nodelist(Node_format * list, uint32_t length, char * client_id)
                 break;
             }
         }
-        if((j - 1) == CLIENT_ID_SIZE)
+        if(j == CLIENT_ID_SIZE)
         {
 
             return 1;
@@ -161,19 +160,18 @@ int get_close_nodes(char * client_id, Node_format * nodes_list)
                 }
                 else for(k = 0; k < MAX_SENT_NODES; k++)
                 {
-                    if(id_closest(client_id, nodes_list[j].client_id, friends_list[i].client_list[j].client_id) == 2)
+                    if(id_closest(client_id, nodes_list[k].client_id, friends_list[i].client_list[j].client_id) == 2)
                     {
-                        memcpy(nodes_list[j].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
+                        memcpy(nodes_list[k].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
-                        nodes_list[j].ip_port = friends_list[i].client_list[j].ip_port;
+                        nodes_list[k].ip_port = friends_list[i].client_list[j].ip_port;
                         break;
                     }
                 }
             }
-            
         }        
-        
     }
     
+    return num_nodes;
 }
 
 
@@ -216,7 +214,7 @@ int replace_good(Client_data * list, uint32_t length, char * client_id, IP_Port
 }
 
 //Attempt to add client with ip_port and client_id to the friends client list and close_clientlist
-int addto_lists(IP_Port ip_port, char * client_id)
+void addto_lists(IP_Port ip_port, char * client_id)
 {
     uint32_t i;
     
@@ -295,6 +293,7 @@ int is_gettingnodes(IP_Port ip_port)
 
 //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.
 //TODO: Maybe optimize this
 int add_pinging(IP_Port ip_port)
 {
@@ -313,6 +312,7 @@ int add_pinging(IP_Port ip_port)
             }
         }
     }
+    return 0;
 }
 
 //Same but for get node requests
@@ -333,10 +333,12 @@ int add_gettingnodes(IP_Port ip_port)
             }
         }
     }
+    return 0;
 }
 
 
 //send a ping request
+//Ping request only works if there is none hos been sent to that ip/port in the last 5 seconds.
 int pingreq(IP_Port ip_port)
 {
     if(is_pinging(ip_port))
@@ -345,6 +347,10 @@ int pingreq(IP_Port ip_port)
     }
     
     int ping_id = add_pinging(ip_port);
+    if(ping_id == 0)
+    {
+        return 1;
+    }
     
     char data[5 + CLIENT_ID_SIZE];
     data[0] = 0;
@@ -377,7 +383,12 @@ int getnodes(IP_Port ip_port, char * client_id)
         return 1;
     }
     
-    int ping_id = add_pinging(ip_port);
+    int ping_id = add_gettingnodes(ip_port);
+    
+    if(ping_id == 0)
+    {
+        return 1;
+    }
     
     char data[5 + CLIENT_ID_SIZE*2];
     data[0] = 2;
@@ -392,15 +403,20 @@ int getnodes(IP_Port ip_port, char * client_id)
 
 //send a send nodes response
 //Currently incomplete: missing bunch of stuff
-int sendnodes(IP_Port ip_port, char * client_id)
+int sendnodes(IP_Port ip_port, char * client_id, uint32_t ping_id)
 {
    char data[5 + (CLIENT_ID_SIZE + sizeof(IP_Port))*MAX_SENT_NODES];
+   Node_format nodes_list[MAX_SENT_NODES];
+   
+   int num_nodes = get_close_nodes(client_id, nodes_list);
+   
    data[0] = 3;
    
+   memcpy(data + 1, &ping_id, 4);
    memcpy(data + 5, self_client_id, CLIENT_ID_SIZE);
-   memcpy(data + 5 + CLIENT_ID_SIZE, client_id, CLIENT_ID_SIZE);
+   memcpy(data + 5 + CLIENT_ID_SIZE, nodes_list, num_nodes * (CLIENT_ID_SIZE + sizeof(IP_Port)));
    
-   sendpacket(ip_port, data, sizeof(data));
+   return sendpacket(ip_port, data, sizeof(data));
 }
 
 
@@ -420,6 +436,8 @@ int handle_pingreq(char * packet, uint32_t length, IP_Port source)
     
     memcpy(&ping_id, packet + 1, 4);
     pingres(source, ping_id);
+    
+    pingreq(source);
  
     return 0;
 }
@@ -432,6 +450,7 @@ int handle_pingres(char * packet, uint32_t length, IP_Port source)
     }
     
     addto_lists(source, packet + 5);
+    return 0;
 }
 
 int handle_getnodes(char * packet, uint32_t length, IP_Port source)
@@ -440,9 +459,9 @@ int handle_getnodes(char * packet, uint32_t length, IP_Port source)
     {
         return 1;
     }
-    //sendnodes(IP_Port ip_port, char * client_id)
+    uint32_t ping_id;
-    
+    memcpy(&ping_id, packet + 1, 4);
-    
+    sendnodes(source, packet + 5 + CLIENT_ID_SIZE, ping_id);
     
     return 0;
 }
@@ -454,8 +473,19 @@ int handle_sendnodes(char * packet, uint32_t length, IP_Port source)
     {
         return 1;
     } 
-    addto_lists(source, packet + 5);
+    int num_nodes = (length - 5) / (CLIENT_ID_SIZE + sizeof(IP_Port));
+    uint32_t i;
     
+    Node_format nodes_list[MAX_SENT_NODES];
+    memcpy(nodes_list, packet + 5, num_nodes);
+    
+    for(i = 0; i < num_nodes; i++)
+    {
+        pingreq(nodes_list[i].ip_port);
+    }
+    
+    addto_lists(source, packet + 5);
+    return 0;
 }
 
 //END of packet handling functions
@@ -492,14 +522,33 @@ char delfriend(char * client_id)
 
 
 
-
+//TODO: Optimize this.
 IP_Port getfriendip(char * client_id)
 {
+    uint32_t i, j;
+    IP_Port empty = {{{0}}, 0};
     
-    
+    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++)
+            {
+                if(memcmp(friends_list[i].client_list[j].client_id, client_id, CLIENT_ID_SIZE) == 0)
+                {
+                    return friends_list[i].client_list[j].ip_port;
+                }
+                
+            }
+                
+            return empty;
+        }
+    }
+    empty.ip.i = 1;
+    return empty;
 }
-
+    
+    
 
 
 
@@ -507,17 +556,17 @@ int DHT_recvpacket(char * packet, uint32_t length, IP_Port source)
 {
     switch (packet[0]) {
     case 0:
-        handle_pingreq(packet, length, source);
+        return handle_pingreq(packet, length, source);   
-        break;        
+        
     case 1:
-        handle_pingres(packet, length, source);
+        return handle_pingres(packet, length, source); 
-        break;        
+        
     case 2:
-        handle_getnodes(packet, length, source);
+        return handle_getnodes(packet, length, source); 
-        break;        
+        
     case 3:
-        handle_sendnodes(packet, length, source);
+        return handle_sendnodes(packet, length, source);
-        break;
+        
     default: 
         return 1;
         
@@ -526,30 +575,60 @@ int DHT_recvpacket(char * packet, uint32_t length, IP_Port source)
 return 0;
 }
 
+//The timeout after which a node is discarded completely.
+#define Kill_NODE_TIMEOUT 300
+
+//ping interval in seconds for each node in our lists.
+#define PING_INTERVAL 60
+
 //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 doFriends()
 {
-    
+    uint32_t i, j;
-    
+    uint32_t temp_time = unix_time();
-    
+    for(i = 0; i < num_friends; i++)
+    {
+        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.
+            {
+                //TODO: Make this better, it only works if the function is called more than once per second.
+                if((temp_time - friends_list[i].client_list[j].timestamp) % PING_INTERVAL == 0)
+                {
+                    pingreq(friends_list[i].client_list[j].ip_port);
+                }
+                //TODO: Send getnodes requests
+            }   
+        }
+    }
 }
 
 
 void doClose()
 {
-    
+    uint32_t i;
-    
+    uint32_t temp_time = unix_time();
-    
+    for(i = 0; i < MAX_FRIEND_CLIENTS; i++)
+    {
+        if(close_clientlist[i].timestamp + Kill_NODE_TIMEOUT > temp_time)//if node is not dead.
+        {
+            //TODO: Make this better, it only works if the function is called more than once per second.
+            if((temp_time - close_clientlist[i].timestamp) % PING_INTERVAL == 0)
+            {
+                pingreq(close_clientlist[i].ip_port);
+            }
+            //TODO: Send getnodes requests
+        }   
+    }    
 }
 
 
 
 void doDHT()
 {
-    
+    doClose();
-    
+    doFriends();
-    
 }
 
 

core/DHT.h

@@ -106,6 +106,7 @@ char delfriend(char * client_id);
 //port must be 2 bytes long.
 //returns ip if success
 //returns ip of 0 if failure (This means the friend is either offline or we have not found him yet.)
+//returns ip of 1 if friend is not in list.
 IP_Port getfriendip(char * client_id);
 
 

testing/DHT_test.c

@@ -16,16 +16,34 @@
 
 #else
 #include <unistd.h>
+#include <arpa/inet.h>
 #define c_sleep(x) usleep(1000*x)
 
 #endif
 
 #define PORT 33445
 
-
+void print_clientlist()
+{
+    uint32_t i, j;
+    IP_Port p_ip;
+    printf("___________________________________________________\n");
+    for(i = 0; i < 4; i++)
+    {
+        printf("ClientID: ");
+        for(j = 0; j < 32; j++)
+        {
+            printf("%c", close_clientlist[i].client_id[j]);
+        }
+        p_ip = close_clientlist[i].ip_port;
+        printf("\nIP: %u.%u.%u.%u Port: %u",p_ip.ip.c[0],p_ip.ip.c[1],p_ip.ip.c[2],p_ip.ip.c[3],ntohs(p_ip.port));
+        printf("\nTimestamp: %u\n", close_clientlist[i].timestamp);
+    }  
+}
 
 int main(int argc, char *argv[])
 {
+    memcpy(self_client_id,"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",32);
     #ifdef WIN32
     WSADATA wsaData;
     if(WSAStartup(MAKEWORD(2,2), &wsaData) != NO_ERROR)
@@ -52,9 +70,9 @@ int main(int argc, char *argv[])
     #endif
     
     //Bind our socket to port PORT and address 0.0.0.0
-    ADDR addr = {.family = AF_INET, .ip.i = 0, .port = htons(PORT)}; 
+    ADDR addr = {AF_INET, htons(PORT), {{0}}}; 
     bind(sock, (struct sockaddr*)&addr, sizeof(addr));
-    
+    perror("Initialization");
     IP_Port bootstrap_ip_port;
     bootstrap_ip_port.port = htons(atoi(argv[2]));
     //bootstrap_ip_port.ip.c[0] = 127;
@@ -75,7 +93,7 @@ int main(int argc, char *argv[])
             
         doDHT();
         
-        if(recievepacket(&ip_port, data, &length) != -1)
+        while(recievepacket(&ip_port, data, &length) != -1)
         {
             if(DHT_recvpacket(data, length, ip_port))
             {
@@ -90,7 +108,8 @@ int main(int argc, char *argv[])
                 printf("Received handled packet with length: %u\n", length);
             }
         }
-        c_sleep(100);
+        print_clientlist();
+        c_sleep(300);
     }
     
     #ifdef WIN32

testing/rect.py

@@ -0,0 +1,19 @@
+#basic python UDP script
+#for testing only
+import socket
+
+UDP_IP = "127.0.0.1"
+UDP_PORT = 5004
+
+sock = socket.socket(socket.AF_INET, # Internet
+                     socket.SOCK_DGRAM) # UDP
+sock.bind((UDP_IP, UDP_PORT))
+
+#send ping request to our DHT on localhost.
+sock.sendto("0012345678".decode("hex") + "HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH", ('127.0.0.1', 33445))
+
+#print all packets recieved and respond to ping requests properly
+while True:
+    data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
+    print "received message:", data, " From:", addr
+    sock.sendto("01".decode('hex') + data[1:5] + "HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH", addr)