Merge pull request #249 from rlt3/master

Re-styling Lossless_UDP.c and .h

2 files changed, 333 insertions, 190 deletions

diff --git a/core/Lossless_UDP.c b/core/Lossless_UDP.c
index 6be8328f..4affc38f 100644
--- a/core/Lossless_UDP.c
+++ b/core/Lossless_UDP.c
@@ -21,67 +21,95 @@
  *
  */
 
-/* TODO: clean this file a bit.
-   There are a couple of useless variables to get rid of. */
+/* 
+ * TODO: clean this file a bit.
+ * There are a couple of useless variables to get rid of.
+ */
+
 #include "Lossless_UDP.h"
 
 /* maximum data packets in sent and receive queues. */
-#define MAX_QUEUE_NUM 16
-
-/* maximum length of the data in the data packets */
-/* #define MAX_DATA_SIZE 1024 */ /* defined in Lossless_UDP.h */
+#define MAX_QUEUE_NUM     16
 
 /* maximum number of data packets in the buffer */
 #define BUFFER_PACKET_NUM (16-1)
 
-/* Lossless UDP connection timeout.
-timeout per connection is randomly set between CONNEXION_TIMEOUT and 2*CONNEXION_TIMEOUT */
+/* timeout per connection is randomly set between CONNEXION_TIMEOUT and 2*CONNEXION_TIMEOUT */
 #define CONNEXION_TIMEOUT 5
 
 /* initial amount of sync/hanshake packets to send per second. */
-#define SYNC_RATE 2
+#define SYNC_RATE         2
 
 /* initial send rate of data. */
-#define DATA_SYNC_RATE 30
+#define DATA_SYNC_RATE    30
 
 typedef struct {
-    uint8_t data[MAX_DATA_SIZE];
+    uint8_t  data[MAX_DATA_SIZE];
     uint16_t size;
 } Data;
 
 typedef struct {
     IP_Port ip_port;
-    uint8_t status; /* 0 if connection is dead, 1 if attempting handshake,
-                       2 if handshake is done (we start sending SYNC packets)
-                       3 if we are sending SYNC packets and can send data
-                       4 if the connection has timed out. */
-
-    uint8_t inbound; /* 1 or 2 if connection was initiated by someone else, 0 if not.
-                        2 if incoming_connection() has not returned it yet, 1 if it has. */
-
-    uint16_t SYNC_rate; /* current SYNC packet send rate packets per second. */
-    uint16_t data_rate; /* current data packet send rate packets per second. */
-    uint64_t last_SYNC; /* time at which our last SYNC packet was sent. */
-    uint64_t last_sent; /* time at which our last data or handshake packet was sent. */
-    uint64_t last_recvSYNC; /* time at which we last received a SYNC packet from the other */
-    uint64_t last_recvdata; /* time at which we last received a DATA packet from the other */
-    uint64_t killat; /* time at which to kill the connection */
-    Data sendbuffer[MAX_QUEUE_NUM]; /* packet send buffer. */
-    Data recvbuffer[MAX_QUEUE_NUM]; /* packet receive buffer. */
-    uint32_t handshake_id1;
-    uint32_t handshake_id2;
-    uint32_t recv_packetnum; /* number of data packets received (also used as handshake_id1) */
-    uint32_t orecv_packetnum; /* number of packets received by the other peer */
-    uint32_t sent_packetnum; /* number of data packets sent */
-    uint32_t osent_packetnum; /* number of packets sent by the other peer. */
-    uint32_t sendbuff_packetnum; /* number of latest packet written onto the sendbuffer */
-    uint32_t successful_sent; /* we know all packets before that number were successfully sent */
-    uint32_t successful_read; /* packet number of last packet read with the read_packet function */
-    uint32_t req_packets[BUFFER_PACKET_NUM]; /* list of currently requested packet numbers(by the other person) */
-    uint16_t num_req_paquets;  /* total number of currently requested packets(by the other person) */
-    uint8_t recv_counter;
-    uint8_t send_counter;
-    uint8_t timeout; /* connection timeout in seconds. */
+
+    /*
+     * 0 if connection is dead, 1 if attempting handshake,
+     * 2 if handshake is done (we start sending SYNC packets)
+     * 3 if we are sending SYNC packets and can send data
+     * 4 if the connection has timed out.
+     */
+    uint8_t status;
+
+    /* 
+     * 1 or 2 if connection was initiated by someone else, 0 if not.
+     * 2 if incoming_connection() has not returned it yet, 1 if it has. 
+     */
+    uint8_t inbound;
+
+    uint16_t  SYNC_rate;     /* current SYNC packet send rate packets per second. */
+    uint16_t  data_rate;     /* current data packet send rate packets per second. */
+
+    uint64_t  last_SYNC;     /* time our last SYNC packet was sent. */
+    uint64_t  last_sent;     /* time our last data or handshake packet was sent. */
+    uint64_t  last_recvSYNC; /* time we last received a SYNC packet from the other */
+    uint64_t  last_recvdata; /* time we last received a DATA packet from the other */
+    uint64_t  killat;        /* time to kill the connection */
+
+    Data      sendbuffer[MAX_QUEUE_NUM]; /* packet send buffer. */
+    Data      recvbuffer[MAX_QUEUE_NUM]; /* packet receive buffer. */
+
+    uint32_t  handshake_id1;
+    uint32_t  handshake_id2;
+
+    /* number of data packets received (also used as handshake_id1) */
+    uint32_t  recv_packetnum; 
+
+    /* number of packets received by the other peer */
+    uint32_t  orecv_packetnum;
+
+    /* number of data packets sent */
+    uint32_t  sent_packetnum; 
+
+    /* number of packets sent by the other peer. */
+    uint32_t  osent_packetnum; 
+
+    /* number of latest packet written onto the sendbuffer */
+    uint32_t  sendbuff_packetnum;
+
+    /* we know all packets before that number were successfully sent */
+    uint32_t  successful_sent; 
+
+    /* packet number of last packet read with the read_packet function */
+    uint32_t  successful_read; 
+
+    /* list of currently requested packet numbers(by the other person) */
+    uint32_t  req_packets[BUFFER_PACKET_NUM]; 
+
+    /* total number of currently requested packets(by the other person) */
+    uint16_t  num_req_paquets;  
+
+    uint8_t   recv_counter;
+    uint8_t   send_counter;
+    uint8_t   timeout; /* connection timeout in seconds. */
 } Connection;
 
 
@@ -94,26 +122,33 @@ static uint32_t connections_number; /* Number of connections in connections arra
 
 /* Functions */
 
-/* get connection id from IP_Port
-   return -1 if there are no connections like we are looking for
-   return id if it found it */
+/* 
+ * Get connection id from IP_Port
+ * Return -1 if there are no connections like we are looking for
+ * Return id if it found it
+ */
 int getconnection_id(IP_Port ip_port)
 {
     uint32_t i;
     for (i = 0; i < MAX_CONNECTIONS; ++i) {
         if (connections[i].ip_port.ip.i == ip_port.ip.i &&
-            connections[i].ip_port.port == ip_port.port && connections[i].status > 0)
+            connections[i].ip_port.port == ip_port.port && 
+            connections[i].status > 0)
             return i;
     }
+
     return -1;
 }
 
 /* table of random numbers used below. */
 static uint32_t randtable[6][256];
 
-/* generate a handshake_id which depends on the ip_port.
-   this function will always give one unique handshake_id per ip_port.
-   TODO: make this better */
+/* 
+ * Generate a handshake_id which depends on the ip_port.
+ * This function will always give one unique handshake_id per ip_port.
+ *
+ * TODO: make this better
+ */
 uint32_t handshake_id(IP_Port source)
 {
     uint32_t id = 0, i;
@@ -124,21 +159,27 @@ uint32_t handshake_id(IP_Port source)
     }
     if (id == 0) /* id can't be zero */
         id = 1;
+
     return id;
 }
 
-/* change the hnshake id associated with that ip_port
-   TODO: make this better */
+/* 
+ * Change the hanshake 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
-   returns an integer corresponding to the connection id.
-   return -1 if it could not initialize the connection.
-   if there already was an existing connection to that ip_port return its number. */
+/* 
+ * Initialize a new connection to ip_port
+ * Returns an integer corresponding to the connection idt
+ * Return -1 if it could not initialize the connectiont
+ * If there already was an existing connection to that ip_port return its number.
+ */
 int new_connection(IP_Port ip_port)
 {
     int connect = getconnection_id(ip_port);
@@ -148,8 +189,10 @@ int new_connection(IP_Port ip_port)
     if(connections_number == connections_length) {
         Connection * temp;
         temp = realloc(connections, sizeof(Connection) * (connections_length + 1));
+
         if(temp == NULL)
             return -1;
+
         memset(&temp[connections_length], 0, sizeof(Connection));
         ++connections_length;
         connections = temp;
@@ -159,31 +202,37 @@ int new_connection(IP_Port ip_port)
     for (i = 0; i < MAX_CONNECTIONS; ++i) {
         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;
-            connections[i].handshake_id1 = handshake_id(ip_port);
-            connections[i].sent_packetnum = connections[i].handshake_id1;
-            connections[i].sendbuff_packetnum = connections[i].handshake_id1;
-            connections[i].successful_sent = connections[i].handshake_id1;
-            connections[i].SYNC_rate = SYNC_RATE;
-            connections[i].data_rate = DATA_SYNC_RATE;
-            connections[i].last_recvSYNC = current_time();
-            connections[i].last_sent = current_time();
-            connections[i].killat = ~0;
-            connections[i].send_counter = 0;
-            /* add randomness to timeout to prevent connections getting stuck in a loop. */
-            connections[i].timeout = CONNEXION_TIMEOUT + rand() % CONNEXION_TIMEOUT;
+
+            connections[i] = (Connection) {
+              .ip_port            = ip_port,
+              .status             = 1,
+              .inbound            = 0,
+              .handshake_id1      = handshake_id(ip_port),
+              .sent_packetnum     = connections[i].handshake_id1,
+              .sendbuff_packetnum = connections[i].handshake_id1,
+              .successful_sent    = connections[i].handshake_id1,
+              .SYNC_rate          = SYNC_RATE,
+              .data_rate          = DATA_SYNC_RATE,
+              .last_recvSYNC      = current_time(),
+              .last_sent          = current_time(),
+              .killat             = ~0,
+              .send_counter       = 0,
+              /* add randomness to timeout to prevent connections getting stuck in a loop. */
+              .timeout            = CONNEXION_TIMEOUT + rand() % CONNEXION_TIMEOUT
+            };
             ++connections_number;
+
             return i;
         }
     }
     return -1;
 }
 
-/* initialize a new inbound connection from ip_port
-   returns an integer corresponding to the connection id.
-   return -1 if it could not initialize the connection. */
+/* 
+ * Initialize a new inbound connection from ip_port
+ * Returns an integer corresponding to the connection id.
+ * Return -1 if it could not initialize the connection.
+ */
 int new_inconnection(IP_Port ip_port)
 {
     if (getconnection_id(ip_port) != -1)
@@ -192,8 +241,10 @@ int new_inconnection(IP_Port ip_port)
     if(connections_number == connections_length) {
         Connection * temp;
         temp = realloc(connections, sizeof(Connection) * (connections_length + 1));
+
         if(temp == NULL)
             return -1;
+
         memset(&temp[connections_length], 0, sizeof(Connection));
         ++connections_length;
         connections = temp;
@@ -203,18 +254,23 @@ int new_inconnection(IP_Port ip_port)
     for (i = 0; i < MAX_CONNECTIONS; ++i) {
         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;
-            connections[i].SYNC_rate = SYNC_RATE;
-            connections[i].data_rate = DATA_SYNC_RATE;
-            connections[i].last_recvSYNC = current_time();
-            connections[i].last_sent = current_time();
-            /* add randomness to timeout to prevent connections getting stuck in a loop. */
-            connections[i].timeout = CONNEXION_TIMEOUT + rand() % CONNEXION_TIMEOUT;
-            /* if this connection isn't handled within the timeout kill it. */
-            connections[i].killat = current_time() + 1000000UL*connections[i].timeout;
-            connections[i].send_counter = 127;
+
+            connections[i] = (Connection){
+                .ip_port       = ip_port,
+                .status        = 2,
+                .inbound       = 2,
+                .SYNC_rate     = SYNC_RATE,
+                .data_rate     = DATA_SYNC_RATE,
+                .last_recvSYNC = current_time(),
+                .last_sent     = current_time(),
+                .send_counter  = 127,
+
+                /* add randomness to timeout to prevent connections getting stuck in a loop. */
+                .timeout       = CONNEXION_TIMEOUT + rand() % CONNEXION_TIMEOUT,
+
+                /* if this connection isn't handled within the timeout kill it. */
+                .killat        = current_time() + 1000000UL*connections[i].timeout
+            };
             ++connections_number;
             return i;
         }
@@ -222,8 +278,10 @@ int new_inconnection(IP_Port ip_port)
     return -1;
 }
 
-/* returns an integer corresponding to the next connection in our incoming connection list
-   return -1 if there are no new incoming connections in the list. */
+/* 
+ * Returns an integer corresponding to the next connection in our incoming connection list.
+ * Return -1 if there are no new incoming connections in the list.
+ */
 int incoming_connection()
 {
     uint32_t i;
@@ -233,9 +291,11 @@ int incoming_connection()
             return i;
         }
     }
+
     return -1;
 }
-/*Try to free some memory from the connections array.*/
+
+/* Try to free some memory from the connections array. */
 static void free_connections()
 {
     uint32_t i;
@@ -245,16 +305,20 @@ static void free_connections()
 
     if(connections_length == i)
         return;
+
     Connection * temp;
     temp = realloc(connections, sizeof(Connection) * i);
     if(temp == NULL && i != 0)
         return;
+
     connections = temp;
     connections_length = i;
 }
 
-/* return -1 if it could not kill the connection.
-   return 0 if killed successfully */
+/* 
+ * Return -1 if it could not kill the connection.
+ * Return 0 if killed successfully
+ */
 int kill_connection(int connection_id)
 {
     if (connection_id >= 0 && connection_id < MAX_CONNECTIONS) {
@@ -269,9 +333,11 @@ int kill_connection(int connection_id)
     return -1;
 }
 
-/* kill connection in seconds seconds.
-   return -1 if it can not kill the connection.
-   return 0 if it will kill it */
+/* 
+ * Kill connection in seconds.
+ * Return -1 if it can not kill the connection.
+ * Return 0 if it will kill it.
+ */
 int kill_connection_in(int connection_id, uint32_t seconds)
 {
     if (connection_id >= 0 && connection_id < MAX_CONNECTIONS) {
@@ -283,12 +349,14 @@ int kill_connection_in(int connection_id, uint32_t seconds)
     return -1;
 }
 
-/* check if connection is connected
-   return 0 no.
-   return 1 if attempting handshake
-   return 2 if handshake is done
-   return 3 if fully connected
-   return 4 if timed out and waiting to be killed */
+/* 
+ * Check if connection is connected:
+ * Return 0 no.
+ * Return 1 if attempting handshake.
+ * Return 2 if handshake is done.
+ * Return 3 if fully connected.
+ * Return 4 if timed out and waiting to be killed.
+ */
 int is_connected(int connection_id)
 {
     if (connection_id >= 0 && connection_id < MAX_CONNECTIONS)
@@ -327,8 +395,10 @@ char id_packet(int connection_id)
 {
     if (connection_id < 0 || connection_id >= MAX_CONNECTIONS)
         return -1;
+
     if (recvqueue(connection_id) != 0 && connections[connection_id].status != 0)
         return connections[connection_id].recvbuffer[connections[connection_id].successful_read % MAX_QUEUE_NUM].data[0];
+
     return -1;
 }
 
@@ -338,7 +408,7 @@ int read_packet(int connection_id, uint8_t * data)
 {
     if (recvqueue(connection_id) != 0) {
         uint16_t index = connections[connection_id].successful_read % MAX_QUEUE_NUM;
-        uint16_t size = connections[connection_id].recvbuffer[index].size;
+        uint16_t size  = connections[connection_id].recvbuffer[index].size;
         memcpy(data, connections[connection_id].recvbuffer[index].data, size);
         ++connections[connection_id].successful_read;
         connections[connection_id].recvbuffer[index].size = 0;
@@ -347,14 +417,15 @@ int read_packet(int connection_id, uint8_t * data)
     return 0;
 }
 
-/* return 0 if data could not be put in packet queue
-   return 1 if data was put into the queue */
+/* 
+ * Return 0 if data could not be put in packet queue
+ * Return 1 if data was put into the queue
+ */
 int write_packet(int connection_id, uint8_t * data, uint32_t length)
 {
-    if (length > MAX_DATA_SIZE)
-        return 0;
-    if (length == 0)
+    if (length > MAX_DATA_SIZE || length == 0)
         return 0;
+
     if (sendqueue(connection_id) <  BUFFER_PACKET_NUM) {
         uint32_t index = connections[connection_id].sendbuff_packetnum % MAX_QUEUE_NUM;
         memcpy(connections[connection_id].sendbuffer[index].data, data, length);
@@ -362,6 +433,7 @@ int write_packet(int connection_id, uint8_t * data, uint32_t length)
         connections[connection_id].sendbuff_packetnum++;
         return 1;
     }
+
     return 0;
 }
 
@@ -371,8 +443,11 @@ uint32_t missing_packets(int connection_id, uint32_t * requested)
     uint32_t number = 0;
     uint32_t i;
     uint32_t temp;
-    if (recvqueue(connection_id) >= (BUFFER_PACKET_NUM - 1)) /* don't request packets if the buffer is full. */
+
+    /* don't request packets if the buffer is full. */
+    if (recvqueue(connection_id) >= (BUFFER_PACKET_NUM - 1)) 
         return 0;
+
     for (i = connections[connection_id].recv_packetnum; i != connections[connection_id].osent_packetnum; i++) {
         if(connections[connection_id].recvbuffer[i % MAX_QUEUE_NUM].size == 0) {
             temp = htonl(i);
@@ -380,14 +455,19 @@ uint32_t missing_packets(int connection_id, uint32_t * requested)
             ++number;
         }
     }
+    
     if(number == 0)
         connections[connection_id].recv_packetnum = connections[connection_id].osent_packetnum;
+
     return number;
 }
 
-/* Packet sending functions
-  One per packet type.
-  see docs/Lossless_UDP.txt for more information. */
+/* 
+ * BEGIN Packet sending functions
+ * One per packet type.
+ * see docs/Lossless_UDP.txt for more information.
+ */
+
 int send_handshake(IP_Port ip_port, uint32_t handshake_id1, uint32_t handshake_id2)
 {
     uint8_t packet[1 + 4 + 4];
@@ -398,21 +478,22 @@ int send_handshake(IP_Port ip_port, uint32_t handshake_id1, uint32_t handshake_i
     memcpy(packet + 1, &temp, 4);
     temp = htonl(handshake_id2);
     memcpy(packet + 5, &temp, 4);
+
     return sendpacket(ip_port, packet, sizeof(packet));
 }
 
 int send_SYNC(uint32_t connection_id)
 {
-
     uint8_t packet[(BUFFER_PACKET_NUM*4 + 4 + 4 + 2)];
     uint16_t index = 0;
 
-    IP_Port ip_port = connections[connection_id].ip_port;
-    uint8_t counter = connections[connection_id].send_counter;
+    IP_Port ip_port         = connections[connection_id].ip_port;
+    uint8_t counter         = connections[connection_id].send_counter;
     uint32_t recv_packetnum = htonl(connections[connection_id].recv_packetnum);
     uint32_t sent_packetnum = htonl(connections[connection_id].sent_packetnum);
+
     uint32_t requested[BUFFER_PACKET_NUM];
-    uint32_t number = missing_packets(connection_id, requested);
+    uint32_t number         = missing_packets(connection_id, requested);
 
     packet[0] = 17;
     index += 1;
@@ -462,17 +543,24 @@ int send_DATA(uint32_t connection_id)
     return 0;
 }
 
-/* END of packet sending functions */
+/* 
+ * END of packet sending functions
+ *
+ *
+ * BEGIN Packet handling functions
+ * One to handle each type of packets we receive
+ */
+
 
-/* Packet handling functions
-   One to handle each type of packets we receive
-   return 0 if handled correctly, 1 if packet is bad. */
+/* Return 0 if handled correctly, 1 if packet is bad. */
 int handle_handshake(uint8_t * packet, uint32_t length, IP_Port source)
 {
     if (length != (1 + 4 + 4))
         return 1;
+
     uint32_t temp;
     uint32_t handshake_id1, handshake_id2;
+
     int connection = getconnection_id(source);
     memcpy(&temp, packet + 1, 4);
     handshake_id1 = ntohl(temp);
@@ -485,21 +573,22 @@ int handle_handshake(uint8_t * packet, uint32_t length, IP_Port source)
     }
     if (is_connected(connection) != 1)
         return 1;
-    if (handshake_id2 == connections[connection].handshake_id1) { /* if handshake_id2 is what we sent previously as handshake_id1 */
+
+    /* if handshake_id2 is what we sent previously as handshake_id1 */
+    if (handshake_id2 == connections[connection].handshake_id1) { 
         connections[connection].status = 2;
         /* NOTE: is this necessary?
         connections[connection].handshake_id2 = handshake_id1; */
         connections[connection].orecv_packetnum = handshake_id2;
         connections[connection].osent_packetnum = handshake_id1;
-        connections[connection].recv_packetnum = handshake_id1;
+        connections[connection].recv_packetnum  = handshake_id1;
         connections[connection].successful_read = handshake_id1;
     }
-    return 0;
 
+    return 0;
 }
 
-/* returns 1 if sync packet is valid
-   0 if not. */
+/* returns 1 if sync packet is valid 0 if not. */
 int SYNC_valid(uint32_t length)
 {
     if (length < 4 + 4 + 2)
@@ -510,19 +599,19 @@ int SYNC_valid(uint32_t length)
     return 1;
 }
 
-/* case 1: */
+/* case 1 in handle_SYNC: */
 int handle_SYNC1(IP_Port source, uint32_t recv_packetnum, uint32_t sent_packetnum)
 {
     if (handshake_id(source) == recv_packetnum) {
         int x = new_inconnection(source);
         if (x != -1) {
-            connections[x].orecv_packetnum = recv_packetnum;
-            connections[x].sent_packetnum = recv_packetnum;
+            connections[x].orecv_packetnum    = recv_packetnum;
+            connections[x].sent_packetnum     = recv_packetnum;
             connections[x].sendbuff_packetnum = recv_packetnum;
-            connections[x].successful_sent = recv_packetnum;
-            connections[x].osent_packetnum = sent_packetnum;
-            connections[x].recv_packetnum = sent_packetnum;
-            connections[x].successful_read = sent_packetnum;
+            connections[x].successful_sent    = recv_packetnum;
+            connections[x].osent_packetnum    = sent_packetnum;
+            connections[x].recv_packetnum     = sent_packetnum;
+            connections[x].successful_read    = sent_packetnum;
 
             return x;
         }
@@ -530,7 +619,7 @@ int handle_SYNC1(IP_Port source, uint32_t recv_packetnum, uint32_t sent_packetnu
     return -1;
 }
 
-/* case 2: */
+/* case 2 in handle_SYNC: */
 int handle_SYNC2(int connection_id, uint8_t counter, uint32_t recv_packetnum, uint32_t sent_packetnum)
 {
     if (recv_packetnum == connections[connection_id].orecv_packetnum) {
@@ -543,7 +632,7 @@ int handle_SYNC2(int connection_id, uint8_t counter, uint32_t recv_packetnum, ui
     }
     return 1;
 }
-/* case 3: */
+/* case 3 in handle_SYNC: */
 int handle_SYNC3(int connection_id, uint8_t counter, uint32_t recv_packetnum, uint32_t sent_packetnum, uint32_t * req_packets,
                  uint16_t number)
 {
@@ -553,17 +642,25 @@ int handle_SYNC3(int connection_id, uint8_t counter, uint32_t recv_packetnum, ui
        uint32_t comp_2 = (sent_packetnum - connections[connection_id].successful_read); */
     uint32_t comp_1 = (recv_packetnum - connections[connection_id].orecv_packetnum);
     uint32_t comp_2 = (sent_packetnum - connections[connection_id].osent_packetnum);
-    if (comp_1 <= BUFFER_PACKET_NUM && comp_2 <= BUFFER_PACKET_NUM && comp_counter < 10 && comp_counter != 0) { /* packet valid */
+
+    /* packet valid */
+    if (comp_1 <= BUFFER_PACKET_NUM && 
+        comp_2 <= BUFFER_PACKET_NUM && 
+        comp_counter < 10 && comp_counter != 0) { 
+
         connections[connection_id].orecv_packetnum = recv_packetnum;
         connections[connection_id].osent_packetnum = sent_packetnum;
         connections[connection_id].successful_sent = recv_packetnum;
-        connections[connection_id].last_recvSYNC = current_time();
-        connections[connection_id].recv_counter = counter;
+        connections[connection_id].last_recvSYNC   = current_time();
+        connections[connection_id].recv_counter    = counter;
+
         ++connections[connection_id].send_counter;
+
         for (i = 0; i < number; ++i) {
             temp = ntohl(req_packets[i]);
             memcpy(connections[connection_id].req_packets + i, &temp, 4 * number);
         }
+
         connections[connection_id].num_req_paquets = number;
         return 0;
     }
@@ -575,6 +672,7 @@ int handle_SYNC(uint8_t *packet, uint32_t length, IP_Port source)
 
     if (!SYNC_valid(length))
         return 1;
+
     int connection = getconnection_id(source);
     uint8_t counter;
     uint32_t temp;
@@ -587,19 +685,27 @@ int handle_SYNC(uint8_t *packet, uint32_t length, IP_Port source)
     recv_packetnum = ntohl(temp);
     memcpy(&temp,packet + 6,  4);
     sent_packetnum = ntohl(temp);
+
     if (number != 0)
         memcpy(req_packets, packet + 10,  4 * number);
+
     if (connection == -1)
         return handle_SYNC1(source, recv_packetnum, sent_packetnum);
+
     if (connections[connection].status ==  2)
-        return handle_SYNC2(connection, counter, recv_packetnum, sent_packetnum);
+        return handle_SYNC2(connection, counter, 
+                            recv_packetnum, sent_packetnum);
+
     if (connections[connection].status ==  3)
-        return handle_SYNC3(connection, counter, recv_packetnum, sent_packetnum, req_packets, number);
+        return handle_SYNC3(connection, counter, recv_packetnum, 
+                            sent_packetnum, req_packets, number);
     return 0;
 }
 
-/* add a packet to the received buffer and set the recv_packetnum of the connection to its proper value.
-   return 1 if data was too big, 0 if not. */
+/* 
+ * Add a packet to the received buffer and set the recv_packetnum of the 
+ * connection to its proper value. Return 1 if data was too big, 0 if not.
+ */
 int add_recv(int connection_id, uint32_t data_num, uint8_t *data, uint16_t size)
 {
     if (size > MAX_DATA_SIZE)
@@ -608,16 +714,22 @@ int add_recv(int connection_id, uint32_t data_num, uint8_t *data, uint16_t size)
     uint32_t i;
     uint32_t maxnum = connections[connection_id].successful_read + BUFFER_PACKET_NUM;
     uint32_t sent_packet = data_num - connections[connection_id].osent_packetnum;
+
     for (i = connections[connection_id].recv_packetnum; i != maxnum; ++i) {
         if (i == data_num) {
             memcpy(connections[connection_id].recvbuffer[i % MAX_QUEUE_NUM].data, data, size);
+
             connections[connection_id].recvbuffer[i % MAX_QUEUE_NUM].size = size;
             connections[connection_id].last_recvdata = current_time();
-            if (sent_packet < BUFFER_PACKET_NUM)
+
+            if (sent_packet < BUFFER_PACKET_NUM) {
                 connections[connection_id].osent_packetnum = data_num;
+            }
+
             break;
         }
     }
+
     for (i = connections[connection_id].recv_packetnum; i != maxnum; ++i) {
         if (connections[connection_id].recvbuffer[i % MAX_QUEUE_NUM].size != 0)
             connections[connection_id].recv_packetnum = i;
@@ -635,25 +747,30 @@ int handle_data(uint8_t *packet, uint32_t length, IP_Port source)
     if (connection == -1)
         return 1;
 
-    if (connections[connection].status != 3) /* Drop the data packet if connection is not connected. */
+    /* Drop the data packet if connection is not connected. */
+    if (connections[connection].status != 3)
         return 1;
 
     if (length > 1 + 4 + MAX_DATA_SIZE || length < 1 + 4 + 1)
         return 1;
+
     uint32_t temp;
     uint32_t number;
     uint16_t size = length - 1 - 4;
 
     memcpy(&temp, packet + 1, 4);
     number = ntohl(temp);
+
     return add_recv(connection, number, packet + 5, size);
 }
 
-/* END of packet handling functions */
+/* 
+ * END of packet handling functions 
+ */
 
 int LosslessUDP_handlepacket(uint8_t *packet, uint32_t length, IP_Port source)
 {
-    switch (packet[0]) { //TODO: check if no break statement is correct???
+    switch (packet[0]) {
     case 16:
         return handle_handshake(packet, length, source);
 
@@ -670,8 +787,10 @@ int LosslessUDP_handlepacket(uint8_t *packet, uint32_t length, IP_Port source)
     return 0;
 }
 
-/* Send handshake requests
-   handshake packets are sent at the same rate as SYNC packets */
+/*
+ * Send handshake requests
+ * handshake packets are sent at the same rate as SYNC packets
+ */
 void doNew()
 {
     uint32_t i;
@@ -684,10 +803,13 @@ void doNew()
             }
 
         /* kill all timed out connections */
-        if ( connections[i].status > 0 && (connections[i].last_recvSYNC + connections[i].timeout * 1000000UL) < temp_time &&
-             connections[i].status != 4)
-            /* kill_connection(i); */
+        if (connections[i].status > 0 && 
+            (connections[i].last_recvSYNC + connections[i].timeout * 1000000UL) < temp_time &&
+            connections[i].status != 4) {
             connections[i].status = 4;
+            /* kill_connection(i); */
+        }
+
         if (connections[i].status > 0 && connections[i].killat < temp_time)
             kill_connection(i);
     }
@@ -720,11 +842,13 @@ void doData()
             }
 }
 
-/* TODO: flow control.
-   automatically adjusts send rates of packets for optimal transmission. */
-
 #define MAX_SYNC_RATE 10
 
+/* 
+ * Automatically adjusts send rates of packets for optimal transmission.
+ *
+ * TODO: flow control.
+ */
 void adjustRates()
 {
     uint32_t i;
@@ -744,8 +868,7 @@ void adjustRates()
     }
 }
 
-/* Call this function a couple times per second
-   It's the main loop. */
+/* Call this function a couple times per second It's the main loop. */
 void doLossless_UDP()
 {
     doNew();
diff --git a/core/Lossless_UDP.h b/core/Lossless_UDP.h
index 033bc480..573e1ab9 100644
--- a/core/Lossless_UDP.h
+++ b/core/Lossless_UDP.h
@@ -33,70 +33,90 @@ extern "C" {
 /* maximum length of the data in the data packets */
 #define MAX_DATA_SIZE 1024
 
-/* Functions */
-
-/* initialize a new connection to ip_port
-    returns an integer corresponding to the connection id.
-    return -1 if it could not initialize the connection.
-    if there already was an existing connection to that ip_port return its number. */
+/* 
+ * Initialize a new connection to ip_port
+ * Returns an integer corresponding to the connection id.
+ * Return -1 if it could not initialize the connection.
+ * Return number if there already was an existing connection to that ip_port.
+ */
 int new_connection(IP_Port ip_port);
 
-/* get connection id from IP_Port
-    return -1 if there are no connections like we are looking for
-    return id if it found it */
+/* 
+ * Get connection id from IP_Port.
+ * Return -1 if there are no connections like we are looking for.
+ * Return id if it found it .
+ */
 int getconnection_id(IP_Port ip_port);
 
-/* returns an integer corresponding to the next connection in our imcoming connection list
-    return -1 if there are no new incoming connections in the list. */
+/* 
+ * Returns an int corresponding to the next connection in our imcoming connection list
+ * Return -1 if there are no new incoming connections in the list.
+ */
 int incoming_connection();
 
-/* return -1 if it could not kill the connection.
-    return 0 if killed successfully */
+/* 
+ * Return -1 if it could not kill the connection.
+ * Return 0 if killed successfully
+ */
 int kill_connection(int connection_id);
 
-/* kill connection in seconds seconds.
-    return -1 if it can not kill the connection.
-    return 0 if it will kill it */
+/* 
+ * Kill connection in seconds seconds.
+ * Return -1 if it can not kill the connection.
+ * Return 0 if it will kill it
+ */
 int kill_connection_in(int connection_id, uint32_t seconds);
 
-/* returns the ip_port of the corresponding connection.
-    return 0 if there is no such connection. */
+/* 
+ * Returns the ip_port of the corresponding connection.
+ * Return 0 if there is no such connection.
+ */
 IP_Port connection_ip(int connection_id);
 
-/* returns the id of the next packet in the queue
-    return -1 if no packet in queue */
+/* 
+ * Returns the id of the next packet in the queue 
+ * Return -1 if no packet in queue 
+ */
 char id_packet(int connection_id);
 
-/* return 0 if there is no received data in the buffer.
-    return length of received packet if successful */
+/* 
+ * Return 0 if there is no received data in the buffer.
+ * Return length of received packet if successful 
+ */
 int read_packet(int connection_id, uint8_t *data);
 
-/* return 0 if data could not be put in packet queue
-    return 1 if data was put into the queue */
+/* 
+ * Return 0 if data could not be put in packet queue
+ * Return 1 if data was put into the queue
+ */
 int write_packet(int connection_id, uint8_t *data, uint32_t length);
 
-/* returns the number of packets in the queue waiting to be successfully sent. */
+/* Returns the number of packets in the queue waiting to be successfully sent. */
 uint32_t sendqueue(int connection_id);
 
-/* returns the number of packets in the queue waiting to be successfully read with read_packet(...) */
+/* 
+ * returns the number of packets in the queue waiting to be successfully 
+ * read with read_packet(...)
+ */
 uint32_t recvqueue(int connection_id);
 
-/* check if connection is connected
-    return 0 no.
-    return 1 if attempting handshake
-    return 2 if handshake is done
-    return 3 if fully connected
-    return 4 if timed out and wating to be killed */
+/* Check if connection is connected:
+ * Return 0 no.
+ * Return 1 if attempting handshake.
+ * Return 2 if handshake is done.
+ * Return 3 if fully connected.
+ * Return 4 if timed out and wating to be killed.
+ */
 int is_connected(int connection_id);
 
-/* Call this function a couple times per second
-    It's the main loop. */
+/* Call this function a couple times per second It's the main loop. */
 void doLossless_UDP();
 
-
-/* if we receive a Lossless_UDP packet we call this function so it can be handled.
-    return 0 if packet is handled correctly.
-    return 1 if it didn't handle the packet or if the packet was shit. */
+/* 
+ * If we receive a Lossless_UDP packet, call this function so it can be handled.
+ * Return 0 if packet is handled correctly.
+ * Return 1 if it didn't handle the packet or if the packet was shit.
+ */
 int LosslessUDP_handlepacket(uint8_t *packet, uint32_t length, IP_Port source);
 
 #ifdef __cplusplus