TCP_NetworkInterface.c

/************************************************************************************
* Copyright (C) 2023                                                               *
* TETCOS, Bangalore. India                                                         *
*                                                                                  *
* Tetcos owns the intellectual property rights in the Product and its content.     *
* The copying, redistribution, reselling or publication of any or all of the       *
* Product or its content without express prior written consent of Tetcos is        *
* prohibited. Ownership and / or any other right relating to the software and all  *
* intellectual property rights therein shall remain at all times with Tetcos.      *
*                                                                                  *
* Author:    Shashi Kant Suman                                                     *
*                                                                                  *
* ---------------------------------------------------------------------------------*/
#include "main.h"
#include "TCP.h"
#include "List.h"
#include "TCP_Header.h"
 
void send_to_network(NetSim_PACKET* packet, PNETSIM_SOCKET s)
{
    PTCP_SEGMENT_HDR hdr = TCP_GET_SEGMENT_HDR(packet);
    print_tcp_log("Sending segment from outgoing tcp, local addr:%s:%d, Remote addr %s:%d, SEQ=%d, ACK=%d,SYN=%d,ACK=%d,RST=%d,URG=%d,FIN=%d,LEN=%d",
                  s->localAddr == NULL ? "0.0.0.0" : s->localAddr->ip->str_ip,
                  s->localAddr == NULL ? 0 : s->localAddr->port,
                  s->remoteAddr == NULL ? "0.0.0.0" : s->remoteAddr->ip->str_ip,
                  s->remoteAddr == NULL ? 0 : s->remoteAddr->port,
                  hdr->SeqNum,
                  hdr->AckNum,
                  hdr->Syn,
                  hdr->Ack,
                  hdr->Rst,
                  hdr->Urg,
                  hdr->Fin,
                  get_seg_len(packet));
 
    packet->pstruTransportData->dStartTime = pstruEventDetails->dEventTime;
    packet->pstruTransportData->dEndTime = pstruEventDetails->dEventTime;
 
    NetSim_EVENTDETAILS pevent;
    memcpy(&pevent, pstruEventDetails, sizeof pevent);
    pevent.dPacketSize = packet->pstruTransportData->dPacketSize;
    if (packet->pstruAppData)
    {
        pevent.nApplicationId = packet->pstruAppData->nApplicationId;
        pevent.nSegmentId = packet->pstruAppData->nSegmentId;
    }
    else
    {
        pevent.nSegmentId = 0;
    }
 
    pevent.nEventType = NETWORK_OUT_EVENT;
    pevent.nPacketId = packet->nPacketId;
    pevent.nProtocolId = fn_NetSim_Stack_GetNWProtocol(pevent.nDeviceId);
    pevent.nSubEventType = 0;
    pevent.pPacket = packet;
    pevent.szOtherDetails = NULL;
    fnpAddEvent(&pevent);
}
 
void packet_arrive_from_network_layer()
{
#ifdef _TEST_TCP_
    if (!pass_test())
    {
        //Packet is dropped by test suite
        fn_NetSim_Packet_FreePacket(pstruEventDetails->pPacket);
        return;
    }
#endif
    NetSim_PACKET* packet = pstruEventDetails->pPacket;
    PNETSIM_SOCKET s = find_socket_at_dest(packet);
    PTCP_SEGMENT_HDR hdr = TCP_GET_SEGMENT_HDR(packet);
    if (s && s->tcb)
    {
        print_tcp_log("\nDevice %d, Time %0.2lf: segment arrives at incoming tcp, local addr:%s:%d, Remote addr %s:%d, SEQ=%d, ACK=%d,SYN=%d,ACK=%d,RST=%d,URG=%d,FIN=%d,LEN=%d",
                      pstruEventDetails->nDeviceId,
                      pstruEventDetails->dEventTime,
                      s->localAddr == NULL ? "0.0.0.0" : s->localAddr->ip->str_ip,
                      s->localAddr == NULL ? 0 : s->localAddr->port,
                      s->remoteAddr == NULL ? "0.0.0.0" : s->remoteAddr->ip->str_ip,
                      s->remoteAddr == NULL ? 0 : s->remoteAddr->port,
                      hdr->SeqNum,
                      hdr->AckNum,
                      hdr->Syn,
                      hdr->Ack,
                      hdr->Rst,
                      hdr->Urg,
                      hdr->Fin,
                      get_seg_len(packet));
 
        update_seq_num_on_receiving(s, packet);
 
        if (s->tcb->tcp_state == TCPCONNECTION_CLOSED)
            packet_arrive_at_closed_state(s, packet);
 
        else if (s->tcb->tcp_state == TCPCONNECTION_LISTEN)
            packet_arrives_at_listen_state(s, packet);
        
        else if (s->tcb->tcp_state == TCPCONNECTION_SYN_SENT)
            packet_arrives_at_synsent_state(s, packet);
 
        else
            packet_arrives_at_incoming_tcp(s, packet);
    }
    else
    {
        print_tcp_log("Packet arrive to TCP for device %d for which there is no connection. Discarding..",
                      pstruEventDetails->nDeviceId);
        fn_NetSim_Packet_FreePacket(pstruEventDetails->pPacket);
        pstruEventDetails->pPacket = NULL;
    }
}