Intercepting FEC packets

src/packet_interface.c

@@ -74,7 +74,7 @@ pkt_status_code pkt_decode_data_fec(const char *data, const size_t len, pkt_t *p
     if ( length > 0 )
         expected_len += CRC_SIZE;
      
-    if ( len != expected_len )
+    if ( len != expected_len && type != PTYPE_FEC)
         return E_UNCONSISTENT; 
 
     // We set the TR to 0 in order to calculcate the CRC on the header

src/receiver_utils.c

@@ -210,6 +210,13 @@ int prepare_ack_to_send(receiver_state_t * state)
 int handle_fec_pkt(receiver_state_t * state, const pkt_t * pkt)
 {
     ASSERT(state != NULL && pkt != NULL);
+    if (state->last_received_in_order > pkt_get_seqnum(pkt))
+    {
+        DEBUG("Received FEC with seqnum %d but wasn't used since last received in order is %d", pkt_get_seqnum(pkt), state->last_received_in_order);
+        return 0;
+    }
+    // Add FEC to state buffer of fec 
+    // See if there's FEC that can be used and update buffer
     return 0;
 }
 
@@ -224,6 +231,9 @@ int handle_fec_pkt(receiver_state_t * state, const pkt_t * pkt)
  */
 int handle_data_pkt(receiver_state_t * state, const pkt_t * pkt)
 {
+    DEBUG("Received data packet seqnum %d with timestamp %d | current_window_size : %d, current_window_start : %d", 
+               pkt_get_seqnum(pkt), pkt_get_timestamp(pkt), state->curr_recv_window, state->recv_window_start);
+               
     if (update_buffer_upon_new_data(state, pkt) != 0)  return -1;
 
     if (prepare_ack_to_send(state) != 0)   return -1;
@@ -297,9 +307,6 @@ int handle_truncated_pkt(receiver_state_t * state, const pkt_t * pkt)
  */ 
 int handle_valid_pkt(receiver_state_t * state, const pkt_t * pkt)
 {
-    // Feck - Not handled for now
-    if (pkt_get_type(pkt) != PTYPE_DATA)    return 0;
-
     // Is it in the receive_window ?
     uint8_t seqnum = pkt_get_seqnum(pkt);
     int in_window  = (seqnum >= state->recv_window_start);
@@ -318,15 +325,16 @@ int handle_valid_pkt(receiver_state_t * state, const pkt_t * pkt)
         
     uint8_t tr = pkt_get_tr(pkt);
     if (tr == 1)
-    {    /* If truncated     */
+    {   /* If truncated */
         return handle_truncated_pkt(state, pkt);
     } else if (pkt_get_type(pkt) == PTYPE_DATA)
-    {    /* Not */
+    {   /* Type DATA    */
         return handle_data_pkt(state, pkt);
     } else if (pkt_get_type(pkt) == PTYPE_FEC) 
-    {
+    {   /* Type FEC     */
         return handle_fec_pkt(state, pkt);
     }
+
     return 0;
 }
 
@@ -355,14 +363,11 @@ int handle_incoming(struct pollfd * pfd, receiver_state_t * state)
     pkt_status_code pkt_status = pkt_decode(buffer, read_bytes, pkt);
     if (pkt_status == 0)
     {
-        DEBUG("Received packet seqnum %d with timestamp %d | current_window_size : %d, current_window_start : %d", 
-               pkt_get_seqnum(pkt), pkt_get_timestamp(pkt), state->curr_recv_window, state->recv_window_start);
         if (handle_valid_pkt(state, (const pkt_t *) pkt) != 0) return -1;
     } else
     {            
-        /* If the packet has been damaged we can discuss if it's better to send a ACK
-        or not but for now we just ignore it */
         DEBUG("Received a damaged packet with %d status.", pkt_status);
+        // See if there's a FEC that can be used and update buffer
         pkt_del(pkt);
         return prepare_ack_to_send(state);
     }