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[unix-history] / usr / src / sys / netinet / tcp_timer.c

/* tcp_timer.c 4.2 81/11/25 */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../h/protosw.h"
#include "../net/inet.h"
#include "../net/inet_pcb.h"
#include "../net/inet_systm.h"
#include "../net/if.h"
#include "../net/imp.h"
#include "../net/ip.h"
#include "../net/ip_var.h"
#include "../net/tcp.h"
#include "../net/tcp_fsm.h"
#include "../net/tcp_var.h"
#include "/usr/include/errno.h"

/*
* Fast timeout routine for processing delayed acks
*/
tcp_fasttimo()
{

}

/*
* Tcp protocol timeout routine called every 500 ms.
* Updates the timers in all active tcb's and
* causes finite state machine actions if timers expire.
*/
tcp_slowtimo()
{
       register struct inpcb *ip;
       register struct tcpcb *tp;
       int s = splnet();
       register short *tmp;
       register int i;
COUNT(TCP_TIMEO);

       /*
        * Search through tcb's and update active timers.
        */
       for (ip = tcb.inp_next; ip != &tcb; ip = ip->inp_next) {
               tp = intotcpcb(ip);
               tmp = &tp->t_init;
               for (i = 0; i < TCPT_NTIMERS; i++) {
                       if (*tmp && --*tmp == 0)
                               (void) tcp_usrreq(tp->t_inpcb->inp_socket,
                                   PRU_SLOWTIMO, (struct mbuf *)0,
                                   (caddr_t)i);
                       tmp++;
               }
               tp->t_xmt++;
       }
       tcp_iss += TCP_ISSINCR/PR_SLOWHZ;               /* increment iss */
       splx(s);
}

/*
* Cancel all timers for TCP tp.
*/
tcp_tcancel(tp)
       struct tcpcb *tp;
{
       register int i;

       for (i = 0; i < TCPT_NTIMERS; i++)
               tp->t_timer[i] = 0;
}

/*
* TCP timer went off processing.
*/
tcp_timers(tp, timer)
       register struct tcpcb *tp;
       int timer;
{

COUNT(TCP_TIMERS);
       switch (timertype) {

       case TCPT_2MSL:
               tcp_close(tp);
               return;

       case TCPT_REXMT:
               tp->t_xmtime <<= 1;
               if (tp->t_xmtime > TCPT_TOOLONG) {
                       tcp_drop(tp, ETIMEDOUT);
                       return;
               }
               tcp_output(tp);
               return;

       case TCPT_PERSIST:
               if (tcp_output(tp) == 0)
                       tp->snd_wnd++, (void) tcp_output(tp), tp->snd_wnd--;

       case TCPT_KEEP:
               return;
       }
}