Annotation of 43BSDTahoe/etc/XNSrouted/timer.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1985 Regents of the University of California.
        !             3:  * All rights reserved.  The Berkeley software License Agreement
        !             4:  * specifies the terms and conditions for redistribution.
        !             5:  *
        !             6:  * Includes material written at Cornell University by Bill Nesheim,
        !             7:  * by permission of the author.
        !             8:  */
        !             9: 
        !            10: 
        !            11: #ifndef lint
        !            12: static char sccsid[] = "@(#)timer.c    5.4 (Berkeley) 2/14/86";
        !            13: #endif not lint
        !            14: 
        !            15: /*
        !            16:  * Routing Table Management Daemon
        !            17:  */
        !            18: #include "defs.h"
        !            19: 
        !            20: int    timeval = -TIMER_RATE;
        !            21: 
        !            22: /*
        !            23:  * Timer routine.  Performs routing information supply
        !            24:  * duties and manages timers on routing table entries.
        !            25:  */
        !            26: timer()
        !            27: {
        !            28:        register struct rthash *rh;
        !            29:        register struct rt_entry *rt;
        !            30:        struct rthash *base = hosthash;
        !            31:        int doinghost = 1, timetobroadcast;
        !            32: 
        !            33:        timeval += TIMER_RATE;
        !            34:        if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0)
        !            35:                ifinit();
        !            36:        timetobroadcast = supplier && (timeval % SUPPLY_INTERVAL) == 0;
        !            37: again:
        !            38:        for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) {
        !            39:                rt = rh->rt_forw;
        !            40:                for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
        !            41:                        /*
        !            42:                         * We don't advance time on a routing entry for
        !            43:                         * a passive gateway or that for our only interface. 
        !            44:                         * The latter is excused because we don't act as
        !            45:                         * a routing information supplier and hence would
        !            46:                         * time it out.  This is fair as if it's down
        !            47:                         * we're cut off from the world anyway and it's
        !            48:                         * not likely we'll grow any new hardware in
        !            49:                         * the mean time.
        !            50:                         */
        !            51:                        if (!(rt->rt_state & RTS_PASSIVE) &&
        !            52:                            (supplier || !(rt->rt_state & RTS_INTERFACE)))
        !            53:                                rt->rt_timer += TIMER_RATE;
        !            54:                        if (rt->rt_timer >= EXPIRE_TIME)
        !            55:                                rt->rt_metric = HOPCNT_INFINITY;
        !            56:                        if (rt->rt_timer >= GARBAGE_TIME) {
        !            57:                                rt = rt->rt_back;
        !            58:                                /* Perhaps we should send a REQUEST for this route? */
        !            59:                                rtdelete(rt->rt_forw);
        !            60:                                continue;
        !            61:                        }
        !            62:                        if (rt->rt_state & RTS_CHANGED) {
        !            63:                                rt->rt_state &= ~RTS_CHANGED;
        !            64:                                /* don't send extraneous packets */
        !            65:                                if (!supplier || timetobroadcast)
        !            66:                                        continue;
        !            67:                                msg->rip_cmd = htons(RIPCMD_RESPONSE);
        !            68:                                msg->rip_nets[0].rip_dst =
        !            69:                                        (satons_addr(rt->rt_dst)).x_net;
        !            70:                                msg->rip_nets[0].rip_metric =
        !            71:                                        htons(min(rt->rt_metric+1, HOPCNT_INFINITY));
        !            72:                                toall(sendmsg);
        !            73:                        }
        !            74:                }
        !            75:        }
        !            76:        if (doinghost) {
        !            77:                doinghost = 0;
        !            78:                base = nethash;
        !            79:                goto again;
        !            80:        }
        !            81:        if (timetobroadcast)
        !            82:                toall(supply);
        !            83:        alarm(TIMER_RATE);
        !            84: }
        !            85: 
        !            86: /*
        !            87:  * On hangup, let everyone know we're going away.
        !            88:  */
        !            89: hup()
        !            90: {
        !            91:        register struct rthash *rh;
        !            92:        register struct rt_entry *rt;
        !            93:        struct rthash *base = hosthash;
        !            94:        int doinghost = 1;
        !            95: 
        !            96:        if (supplier) {
        !            97: again:
        !            98:                for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) {
        !            99:                        rt = rh->rt_forw;
        !           100:                        for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw)
        !           101:                                rt->rt_metric = HOPCNT_INFINITY;
        !           102:                }
        !           103:                if (doinghost) {
        !           104:                        doinghost = 0;
        !           105:                        base = nethash;
        !           106:                        goto again;
        !           107:                }
        !           108:                toall(supply);
        !           109:        }
        !           110:        exit(1);
        !           111: }

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