TCP_ApplicationInterface.c

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/************************************************************************************
* Copyright (C) 2022                                                                *
* 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.       *
*                                                                                   *
* This source code is licensed per the NetSim license agreement.                    *
*                                                                                   *
* No portion of this source code may be used as the basis for a derivative work,    *
* or used, for any purpose other than its intended use per the NetSim license       *
* agreement.                                                                        *
*                                                                                   *
* This source code and the algorithms contained within it are confidential trade    *
* secrets of TETCOS and may not be used as the basis for any other software,        *
* hardware, product or service.                                                     *
*                                                                                   *
* Author:    Shashi Kant Suman                                                      *
*                                                                                   *
* ----------------------------------------------------------------------------------*/
#include "main.h"
#include "TCP.h"
#include "List.h"
 
//Function prototype
void fnConnectCallback(PNETSIM_SOCKET s);
void fnListenCallback(PNETSIM_SOCKET s, NetSim_PACKET*);
 
PSOCKETADDRESS anySocketAddr = NULL;
 
void init_anysockaddr()
{
    anySocketAddr = (PSOCKETADDRESS)calloc(1, sizeof* anySocketAddr);
    anySocketAddr->ip = STR_TO_IP("0.0.0.0", 4);
    anySocketAddr->port = 0;
}
 
PSOCKETADDRESS get_anysockaddr()
{
    return anySocketAddr;
}
 
void tcp_init(NETSIM_ID d)
{
    if (!get_anysockaddr())
        init_anysockaddr();
 
    print_tcp_log("\nDevice %d, Time 0.0: Create socket for listen mode with remote addr 0.0.0.0:0", d);
 
    PNETSIM_SOCKET listenSocket = tcp_create_socket();
 
    add_to_socket_list(d, listenSocket);
 
    PSOCKETADDRESS localsocketAddr = (PSOCKETADDRESS)calloc(1, sizeof* localsocketAddr);
    localsocketAddr->ip = DEVICE_NWADDRESS(d,1);
    localsocketAddr->port = 0;
 
    listenSocket->localAddr = localsocketAddr;
 
    listenSocket->localDeviceId = d;
 
    print_tcp_log("Binding listen socket", d);
 
    tcp_bind(listenSocket, get_anysockaddr());
 
    print_tcp_log("Listening...", d);
    tcp_listen(listenSocket, fnListenCallback);
 
    tcp_create_metrics(listenSocket);
 
}
 
int packet_arrive_from_application_layer()
{
    NetSim_PACKET* packet = GET_PACKET_FROM_APP(false);
 
    ptrSOCKETINTERFACE sId = pstruEventDetails->szOtherDetails;
 
    PNETSIM_SOCKET s = find_socket_at_source(packet);
    
    if (!s)
    {
        
        PNETSIM_SOCKET localSocket = tcp_create_socket();
 
        add_to_socket_list(pstruEventDetails->nDeviceId, localSocket);
 
        PSOCKETADDRESS remotesocketAddr = (PSOCKETADDRESS)calloc(1, sizeof* remotesocketAddr);
        remotesocketAddr->ip = IP_COPY(packet->pstruNetworkData->szDestIP);
        remotesocketAddr->port = packet->pstruTransportData->nDestinationPort;
        
        PSOCKETADDRESS localsocketAddr = (PSOCKETADDRESS)calloc(1, sizeof* localsocketAddr);
        localsocketAddr->ip = IP_COPY(packet->pstruNetworkData->szSourceIP);
        localsocketAddr->port = packet->pstruTransportData->nSourcePort;
 
        localSocket->localDeviceId = packet->nSourceId;
        localSocket->remoteDeviceId = get_first_dest_from_packet(packet);
        localSocket->sId = sId;
        localSocket->appId = pstruEventDetails->nApplicationId;
 
        print_tcp_log("\nDevice %d, Time %0.2lf: Creating socket with local addr %s:%d, Remote addr %s:%d",
                      packet->nSourceId,
                      pstruEventDetails->dEventTime,
                      localsocketAddr->ip->str_ip,
                      localsocketAddr->port,
                      remotesocketAddr->ip->str_ip,
                      remotesocketAddr->port);
        print_tcp_log("Connecting socket...", packet->nSourceId);
        tcp_connect(localSocket,localsocketAddr,remotesocketAddr);
 
    }
    else if (s->waitFromApp)
    {
        print_tcp_log("\nDevice %d, Time %0.2lf:",
                      packet->nSourceId,
                      pstruEventDetails->dEventTime);
 
        if (!s->sId)
        {
            s->appId = pstruEventDetails->nApplicationId;
            s->sId = sId;
        }
        else if (s->sId != sId)
        {
            fnNetSimError("Socket id in TCP (%d) and in application (%d) is mismatched.\n",
                          s->sId, sId);
        }
        send_segment(s);
        s->waitFromApp = false;
    }
    else
    {
        //do nothing. Wait for TCP to complete previous operation
    }
    return 0;
}
 
void fnListenCallback(PNETSIM_SOCKET s, NetSim_PACKET* p)
{
    print_tcp_log("Accepting Connection...");
    PNETSIM_SOCKET localSocket = tcp_accept(s, p);
}
 
void send_to_application(PNETSIM_SOCKET s, NetSim_PACKET* p)
{
    NetSim_EVENTDETAILS pevent;
    
    if (p->pstruAppData) //Send only app layer packet
    {
        memcpy(&pevent, pstruEventDetails, sizeof pevent);
        pevent.dPacketSize = p->pstruAppData->dPacketSize;
        pevent.nApplicationId = p->pstruAppData->nApplicationId;
        pevent.nEventType = APPLICATION_IN_EVENT;
        pevent.nPacketId = p->nPacketId;
        pevent.nProtocolId = PROTOCOL_APPLICATION;
        pevent.nSegmentId = p->pstruAppData->nSegmentId;
        pevent.nSubEventType = 0;
        pevent.pPacket = p;
        pevent.szOtherDetails = NULL;
        fnpAddEvent(&pevent);
    }
 
    NetSim_PACKET* pr;
    while(true) 
    {
        pr = check_for_other_segment_to_send_from_queue(s);
        if (!pr)
            break;
 
        if(!pr->pstruAppData)
            continue;
 
        memcpy(&pevent, pstruEventDetails, sizeof pevent);
        pevent.dPacketSize = pr->pstruAppData->dPacketSize;
        pevent.nApplicationId = pr->pstruAppData->nApplicationId;
        pevent.nEventType = APPLICATION_IN_EVENT;
        pevent.nPacketId = pr->nPacketId;
        pevent.nProtocolId = PROTOCOL_APPLICATION;
        pevent.nSegmentId = pr->pstruAppData->nSegmentId;
        pevent.nSubEventType = 0;
        pevent.pPacket = pr;
        pevent.szOtherDetails = NULL;
        fnpAddEvent(&pevent);
 
    }
}