date and time created 81/11/24 17:35:58 by wnj

SCCS-vsn: sys/netinet/tcp_timer.c 4.1

diff --git a/usr/src/sys/netinet/tcp_timer.c b/usr/src/sys/netinet/tcp_timer.c
new file mode 100644 (file)
index 0000000..34b8e5d
--- /dev/null
+++ b/usr/src/sys/netinet/tcp_timer.c
@@ -0,0 +1,140 @@
+/* tcp_timer.c 4.1 81/11/24 */
+
+#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 < TNTIMERS; 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 += ISSINCR/2;           /* increment iss */
+       splx(s);
+}
+
+/*
+ * Cancel all timers for tcp tp.
+ */
+tcp_tcancel(tp)
+       struct tcpcb *tp;
+{
+       register short *tmp = &tp->t_init;
+       register int i;
+
+       for (i = 0; i < TNTIMERS; i++)
+               *tmp++ = 0;
+}
+
+/*
+ * TCP timer went off processing.
+ */
+tcp_timers(tp, timertype)
+       register struct tcpcb *tp;
+       int timertype;
+{
+
+COUNT(TCP_TIMERS);
+       switch (timertype) {
+
+       case TFINACK:           /* fin-ack timer */
+               switch (tp->t_state) {
+
+               case TIME_WAIT:
+                       /*
+                        * We can be sure our ACK of foreign FIN was rcvd,
+                        * and can close if no data left for user.
+                        */
+                       if (rcv_empty(tp)) {
+                               tcp_disconnect(tp);
+                               return (CLOSED);
+                       }
+                       return (RCV_WAIT);                      /* 17 */
+
+               case CLOSING:
+                       tp->tc_flags |= TC_WAITED_2_ML;
+                       return (SAME);
+
+               default:
+                       return (SAME);
+               }
+
+       case TREXMT:            /* retransmission timer */
+               if (tp->t_rexmt_val > tp->snd_una) {            /* 34 */
+                       /*
+                        * Set so for a retransmission, increase rexmt time
+                        * in case of multiple retransmissions.
+                        */
+                       tp->snd_nxt = tp->snd_una;
+                       tp->tc_flags |= TC_REXMT;
+                       tp->t_xmtime = tp->t_xmtime << 1;
+                       if (tp->t_xmtime > T_REMAX)
+                               tp->t_xmtime = T_REMAX;
+                       (void) tcp_send(tp);
+               }
+               return (SAME);
+
+       case TREXMTTL:          /* retransmit too long */
+               if (tp->t_rtl_val > tp->snd_una) {              /* 36 */
+                       tcp_error(tp, ETIMEDOUT);
+                       return (CLOSED);
+               }
+               return (SAME);
+
+       case TPERSIST:          /* persist timer */
+               /*
+                * Force a byte send through closed window.
+                */
+               tp->tc_flags |= TC_FORCE_ONE;
+               (void) tcp_send(tp);
+               return (SAME);
+       }
+       panic("tcp_timers");
+       /*NOTREACHED*/
+}