tcprwindow
/*------------------------------------------------------------------------ * tcprwindow - do receive window processing for a TCB *------------------------------------------------------------------------ */ int tcprwindow(struct tcb *ptcb) { int window; window = ptcb->tcb_rbsize - ptcb->tcb_rbcount; if (ptcb->tcb_state < TCPS_ESTABLISHED) return window; /* * Receiver-Side Silly Window Syndrome Avoidance: * Never shrink an already-advertised window, but wait for at * least 1/4 receiver buffer and 1 max-sized segment before * opening a zero window. */ if (window*4 < (int)ptcb->tcb_rbsize || window < (int)ptcb->tcb_rmss) window = 0; window = max(window, ptcb->tcb_cwin - ptcb->tcb_rnext); ptcb->tcb_cwin = ptcb->tcb_rnext + window; return window; }