99 lines
3.2 KiB
C
99 lines
3.2 KiB
C
/*
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Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "ffd.h"
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#include "neigh.h"
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bool ffd_is_feasible(const ffd_announce_t *announce, ffd_metric_seqno_t ms) {
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if (FFD_IS_INFINITY(ms) || FFD_IS_INFINITY(announce->feasibility_distance))
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return true;
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int16_t seqno_diff = ms.seqno - announce->feasibility_distance.seqno;
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if (seqno_diff < 0)
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return true;
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if (seqno_diff == 0 && ms.metric < announce->feasibility_distance.metric)
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return true;
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return false;
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}
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static ffd_nexthop_t* select_nexthop(const ffd_announce_t *announce) {
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uint16_t ret_metric = 0xffff;
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ffd_nexthop_t *ret = NULL;
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ffd_nexthop_t *nexthop;
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for (nexthop = announce->nexthop_list; nexthop; nexthop = nexthop->next) {
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if (!ffd_is_feasible(announce, nexthop->metric_seqno))
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continue;
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uint32_t metric = nexthop->metric_seqno.metric + ffd_neigh_get_cost(nexthop->neigh);
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if (metric < ret_metric) {
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ret = nexthop;
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ret_metric = metric;
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}
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}
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return ret;
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}
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ffd_metric_seqno_t ffd_announce_get_metric(const ffd_announce_t *announce) {
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if (announce->selected) {
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uint32_t metric = announce->selected->metric_seqno.metric + ffd_neigh_get_cost(announce->selected->neigh);
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if (metric < 0xffff)
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return (ffd_metric_seqno_t){metric, announce->selected->metric_seqno.seqno};
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}
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return (ffd_metric_seqno_t){0xffff, 0};
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}
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static inline void update_selected(ffd_announce_t *announce) {
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announce->selected = select_nexthop(announce);
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}
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void ffd_announce_update(ffd_announce_t *announce, ffd_nexthop_t *nexthop, ffd_metric_seqno_t ms, uint16_t interval) {
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nexthop->metric_seqno = ms;
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nexthop->interval = interval;
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if (ms.metric != 0xffff)
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nexthop->last_update = now;
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update_selected(announce);
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}
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ffd_announce_t* ffd_announce_new(void) {
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ffd_announce_t *a = calloc(1, sizeof(ffd_announce_t));
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a->feasibility_distance.metric = 0xffff;
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a->next = announce_list;
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announce_list = a;
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return a;
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}
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