WindowScale.c

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/************************************************************************************
* Copyright (C) 2020                                                               *
* 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 "TCP_Header.h"
 
void set_window_scaling(PNETSIM_SOCKET s, PWsopt opt)
{
    if (opt)
    {
        s->tcb->isWindowScaling = true;
        s->tcb->Snd.Wind_Shift = opt->Shift_cnt;
        s->tcb->Rcv.Wind_Shift = opt->Shift_cnt;
        s->tcb->RCV.WND = s->tcb->get_RCVWND(s);
    }
    else
    {
        s->tcb->isWindowScaling = false;
        s->tcb->Snd.Wind_Shift = 0;
        s->tcb->Rcv.Wind_Shift = 0;
    }
}
 
UINT8 get_shift_count(PNETSIM_SOCKET s)
{
    return s->tcb->isWindowScaling ? s->tcb->Snd.Wind_Shift : 0;
}
 
void set_window_scaling_option(PNETSIM_SOCKET s, PTCP_DEV_VAR tcp)
{
    if (tcp->isWindowScaling)
    {
        s->tcb->isWindowScaling = true;
        s->tcb->Snd.Wind_Shift = tcp->shiftCount;
        s->tcb->Rcv.Wind_Shift = tcp->shiftCount;
    }
}
 
UINT32 window_scale_get_cwnd(PNETSIM_SOCKET s)
{
    UINT32 c = (UINT32)s->tcb->get_WND(s);
    if (s->tcb->isWindowScaling)
    {
        UINT32 r = c << s->tcb->Snd.Wind_Shift;
        UINT32 mss = s->tcb->get_MSS(s);
        return max(r, mss);
    }
    else
        return (c);
}
 
UINT16 window_scale_get_wnd(PNETSIM_SOCKET s)
{
    if (s->tcb->isWindowScaling)
        return (UINT16)(s->tcb->SND.WND >> s->tcb->Snd.Wind_Shift);
    else
        return (UINT16)(s->tcb->SND.WND);
}