Basic IM messenger backend pretty much done (You can start the GUI)

And a couple of fixes to the other parts.

core/Lossless_UDP.c

@@ -37,7 +37,7 @@
 #define BUFFER_PACKET_NUM (16-1)
 
 //Lossless UDP connection timeout.
-#define CONNEXION_TIMEOUT 10
+#define CONNEXION_TIMEOUT 5
 
 //initial amount of sync/hanshake packets to send per second.
 #define SYNC_RATE 10
@@ -133,7 +133,13 @@ uint32_t handshake_id(IP_Port source)
     }
     return id;
 }
-
+//change the hnshake id associated with that ip_port
+//TODO: make this better
+void change_handshake(IP_Port source)
+{
+    uint8_t rand = random_int() % 4;
+    randtable[rand][((uint8_t *)&source)[rand]] = random_int();
+}
 
 
 //initialize a new connection to ip_port
@@ -152,6 +158,7 @@ int new_connection(IP_Port ip_port)
     {
         if(connections[i].status == 0)
         {
+            memset(&connections[i], 0, sizeof(Connection));
             connections[i].ip_port = ip_port;
             connections[i].status = 1;
             connections[i].inbound = 0;
@@ -184,6 +191,7 @@ int new_inconnection(IP_Port ip_port)
     {
         if(connections[i].status == 0)
         {
+            memset(&connections[i], 0, sizeof(Connection));
             connections[i].ip_port = ip_port;
             connections[i].status = 2;
             connections[i].inbound = 2;
@@ -223,6 +231,7 @@ int kill_connection(int connection_id)
         if(connections[connection_id].status > 0)
         {
                 connections[connection_id].status = 0;
+                change_handshake(connections[connection_id].ip_port);
                 return 0;
         }
     }

core/Messenger.c

@@ -45,6 +45,17 @@ int m_addfriend(uint8_t * client_id)
     return numfriends - 1;
 }
 
+int m_addfriend_norequest(uint8_t * client_id)
+{
+    DHT_addfriend(client_id);
+    friendlist[numfriends].status = 2;
+    friendlist[numfriends].friend_request_id = -1;
+    memcpy(friendlist[numfriends].client_id, client_id, CLIENT_ID_SIZE);
+    numfriends++;
+    
+    return numfriends - 1;
+}
+
 //remove a friend
 int m_delfriend(int friendnumber)
 {/*
@@ -74,7 +85,11 @@ int m_friendstatus(int friendnumber)
 //return 0 if it was not.
 int m_sendmessage(int friendnumber, uint8_t * message, uint32_t length)
 {
-    if(length >= MAX_DATA_SIZE)
+    if(friendnumber < 0 || friendnumber >= MAX_NUM_FRIENDS)
+    {
+        return 0;
+    }
+    if(length >= MAX_DATA_SIZE || friendlist[friendnumber].status != 4)
     //this does not mean the maximum message length is MAX_DATA_SIZE - 1, it is actually 17 bytes less.
     {
         return 0;   
@@ -103,7 +118,7 @@ int m_setinfo(uint8_t * data, uint16_t length)
 void (*friend_request)(uint8_t *, uint8_t *, uint16_t);
 
 //set the function that will be executed when a friend request is received.
-int m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t))
+void m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t))
 {
     friend_request = function;
 }
@@ -112,7 +127,7 @@ int m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t))
 void (*friend_message)(int, uint8_t *, uint16_t);
 
 //set the function that will be executed when a message from a friend is received.
-int m_callback_friendmessage(void (*function)(int, uint8_t *, uint16_t))
+void m_callback_friendmessage(void (*function)(int, uint8_t *, uint16_t))
 {
     friend_message = function;
 }
@@ -146,14 +161,13 @@ void doFriends()
              if(friendip.ip.i > 1 && request == -1)
              {
                   friendlist[i].friend_request_id = send_friendrequest(friendlist[i].client_id, friendip, info, info_size);
-             }
-             if(request == 1)
-             {
                   friendlist[i].status = 2;
              }
         }
         if(friendlist[i].status == 2 || friendlist[i].status == 3)
         {
+            check_friendrequest(friendlist[i].friend_request_id);//for now this is used to kill the friend request
+            
             IP_Port friendip = DHT_getfriendip(friendlist[i].client_id);
             if(is_cryptoconnected(friendlist[i].crypt_connection_id) == 0 && friendip.ip.i > 1)
             {
@@ -163,6 +177,10 @@ void doFriends()
             {
                  friendlist[i].status = 4;
             }
+            if(is_cryptoconnected(friendlist[i].crypt_connection_id) == 4)
+            {
+                crypto_kill(friendlist[i].crypt_connection_id);
+            }
         }
         while(friendlist[i].status == 4)
         {
@@ -200,6 +218,45 @@ void doFriendRequest()
     }
 
 }
+
+
+//return the friend id associated to that public key.
+//return -1 if no such friend
+int getfriend_id(uint8_t * public_key)
+{
+    uint32_t i;
+    for(i = 0; i < numfriends; i++)
+    {
+        if(friendlist[i].status > 0)
+        {
+            if(memcmp(public_key, friendlist[i].client_id, crypto_box_PUBLICKEYBYTES) == 0)
+            {
+                return i;
+            }
+        }
+    }
+    return -1;
+}
+
+void doInbound()
+{
+    uint8_t secret_nonce[crypto_box_NONCEBYTES];
+    uint8_t public_key[crypto_box_PUBLICKEYBYTES];
+    uint8_t session_key[crypto_box_PUBLICKEYBYTES];
+    int inconnection = crypto_inbound(public_key, secret_nonce, session_key);
+    if(inconnection != -1)
+    {
+        int friend_id = getfriend_id(public_key);
+        if(friend_id != -1)
+        {
+             friendlist[friend_id].crypt_connection_id = 
+             accept_crypto_inbound(inconnection, public_key, secret_nonce, session_key);
+             
+             friendlist[friend_id].status = 3;
+        }
+    }
+}
+
 //the main loop that needs to be run at least 200 times per second.
 void doMessenger()
 {
@@ -224,6 +281,7 @@ void doMessenger()
     doDHT();
     doLossless_UDP();
     doNetCrypto();
+    doInbound();
     doFriendRequest();
     doFriends();
 }

core/Messenger.h

@@ -18,6 +18,12 @@
 int m_addfriend(uint8_t * client_id);
 
 
+//add a friend without sending a friendrequest.
+//returns the friend number if success
+//return -1 if failure.
+int m_addfriend_norequest(uint8_t * client_id);
+
+
 //remove a friend
 int m_delfriend(int friendnumber);
 
@@ -36,12 +42,12 @@ int m_setinfo(uint8_t * data, uint16_t length);
 
 //set the function that will be executed when a friend request is received.
 //function format is function(uint8_t * public_key, uint8_t * data, uint16_t length)
-int m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t));
+void m_callback_friendrequest(void (*function)(uint8_t *, uint8_t *, uint16_t));
 
 
 //set the function that will be executed when a message from a friend is received.
 //function format is: function(int friendnumber, uint8_t * message, uint32_t length)
-int m_callback_friendmessage(void (*function)(int, uint8_t *, uint16_t));
+void m_callback_friendmessage(void (*function)(int, uint8_t *, uint16_t));
 
 
 //run this at startup

core/net_crypto.c

@@ -383,7 +383,8 @@ int handle_friendrequest(uint8_t * public_key, uint8_t * data)
                                                     len - (crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES + 1), data);
                     if(len1 != -1)
                     {
-                        kill_connection_in(incoming_connections[i], 1); //conection is useless now, kill it in 1 seconds
+                        kill_connection(incoming_connections[i]);
+                        //kill_connection_in(incoming_connections[i], 1); //conection is useless now, kill it in 1 seconds
                         incoming_connections[i] = -1;
                         return len1;
                     }
@@ -396,6 +397,25 @@ int handle_friendrequest(uint8_t * public_key, uint8_t * data)
     return -1;
 }
 
+//get crypto connection id from public key of peer
+//return -1 if there are no connections like we are looking for
+//return id if it found it
+int getcryptconnection_id(uint8_t * public_key)
+{
+    uint32_t i;
+    for(i = 0; i < MAX_CRYPTO_CONNECTIONS; i++)
+    {
+        if(crypto_connections[i].status > 0)
+        {
+            if(memcmp(public_key, crypto_connections[i].public_key, crypto_box_PUBLICKEYBYTES) == 0)
+            {
+                return i;
+            }
+        }
+    }
+    return -1;
+}
+
 
 //Start a secure connection with other peer who has public_key and ip_port
 //returns -1 if failure
@@ -403,7 +423,7 @@ int handle_friendrequest(uint8_t * public_key, uint8_t * data)
 int crypto_connect(uint8_t * public_key, IP_Port ip_port)
 {
     uint32_t i;
-    if(getconnection_id(ip_port) != -1)
+    if(getcryptconnection_id(public_key) != -1)
     {
         return -1;
     }
@@ -493,6 +513,10 @@ int accept_crypto_inbound(int connection_id, uint8_t * public_key, uint8_t * sec
     {
         return -1;
     }
+    if(getcryptconnection_id(public_key) != -1)
+    {
+        return -1;
+    }
     for(i = 0; i < MAX_CRYPTO_CONNECTIONS; i++)
     {
         if(crypto_connections[i].status == 0)
@@ -584,13 +608,22 @@ void receive_crypto()
     {
         if(crypto_connections[i].status == 1)
         {
+            uint8_t temp_data[MAX_DATA_SIZE];
+            uint8_t secret_nonce[crypto_box_NONCEBYTES];
+            uint8_t public_key[crypto_box_PUBLICKEYBYTES];
+            uint8_t session_key[crypto_box_PUBLICKEYBYTES];
+            uint16_t len;
+            if(id_packet(crypto_connections[i].number) == 1) 
+            //if the packet is a friend request drop it (because we are already friends)
+            {
+                len = read_packet(crypto_connections[i].number, temp_data);
+                printf("REQUEST DROPPED\n");
+                
+            }
             if(id_packet(crypto_connections[i].number) == 2)//handle handshake packet.
             {
-                uint8_t temp_data[MAX_DATA_SIZE];
+
-                uint8_t secret_nonce[crypto_box_NONCEBYTES];
+                len = read_packet(crypto_connections[i].number, temp_data);
-                uint8_t public_key[crypto_box_PUBLICKEYBYTES];
-                uint8_t session_key[crypto_box_PUBLICKEYBYTES];
-                uint16_t len = read_packet(crypto_connections[i].number, temp_data);
                 if(handle_cryptohandshake(public_key, secret_nonce, session_key, temp_data, len))
                 {
                     if(memcmp(public_key, crypto_connections[i].public_key, crypto_box_PUBLICKEYBYTES) == 0)
@@ -660,7 +693,7 @@ void killTimedout()
     uint32_t i;
     for(i = 0; i < MAX_CRYPTO_CONNECTIONS; i++)
     {
-        if(is_connected(crypto_connections[i].number) == 4)
+        if(crypto_connections[i].status != 0 && is_connected(crypto_connections[i].number) == 4)
         {
             crypto_connections[i].status = 4;
         }

testing/Messenger_test.c

@@ -42,12 +42,22 @@ void print_request(uint8_t * public_key, uint8_t * data, uint16_t length)
     }
     printf("\nOf length: %u with data: %s \n", length, data);
     
+    if(length != sizeof("Install Gentoo"))
+    {
+        return;
+    }
+    if(memcmp(data ,"Install Gentoo", sizeof("Install Gentoo")) == 0 )
+    //if the request contained the message of peace the person is obviously a friend so we add him.
+    {
+        printf("Friend request accepted.\n");
+        m_addfriend_norequest(public_key);
+    }
 }
 
 void print_message(int friendnumber, uint8_t * string, uint16_t length)
 {
     printf("Message with length %u recieved from %u: %s \n", length, friendnumber, string);
-    
+    m_sendmessage(friendnumber, "Test1", 6);
 }
 
 int main(int argc, char *argv[])
@@ -86,7 +96,7 @@ int main(int argc, char *argv[])
     {
         m_sendmessage(num, "Test", 5);
         doMessenger();
-        c_sleep(1);
+        c_sleep(30);
     }
     
 }