From 3969d78ac46133dba88949f4996c564be97e1a71 Mon Sep 17 00:00:00 2001
From: ingenzi <vany.ingenzi@student.uclouvain.be>
Date: Sun, 10 Apr 2022 10:12:37 +0200
Subject: [PATCH] Intercepting FEC packets
---
src/packet_interface.c | 2 +-
src/receiver_utils.c | 25 +++++++++++++++----------
2 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/src/packet_interface.c b/src/packet_interface.c
index 7193b58..783380c 100644
--- a/src/packet_interface.c
+++ b/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
diff --git a/src/receiver_utils.c b/src/receiver_utils.c
index 423b4a2..f8cfc56 100644
--- a/src/receiver_utils.c
+++ b/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);
}
--
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