From 47bd032564a4812a607cbe9f5a44ef2b2f93278d Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Sun, 24 Mar 2013 03:45:16 +0100
Subject: Initial nexthop maintenance implementation

Mostly taken from the FFD project, and quite incomplete.
---
 src/announce.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 111 insertions(+), 1 deletion(-)

(limited to 'src/announce.c')

diff --git a/src/announce.c b/src/announce.c
index 1891341..1d17a02 100644
--- a/src/announce.c
+++ b/src/announce.c
@@ -33,7 +33,7 @@
 gp_babel_announce_t* gp_babel_announce_new(gmrf_t *gmrf, gmrf_context_t *ctx) {
 	gp_babel_announce_t *a = calloc(1, sizeof(gp_babel_announce_t));
 
-	a->metric.metric = a->feasibility_distance.metric = a->last_metric = 0xffff;
+	a->metric.metric = a->feasibility_distance.metric = a->last_metric = GP_BABEL_INFINITY;
 
 	a->next = ctx->announces;
 	ctx->announces = a;
@@ -91,3 +91,113 @@ gp_babel_nexthop_t* gp_babel_announce_nexthop_new(gp_babel_announce_t *announce,
 
 	return nexthop;
 }
+
+static void maintain_nexthops(gmrf_t *gmrf, gp_babel_announce_t *announce) {
+	gp_babel_nexthop_t **cur, **next;
+	for (cur = &announce->nexthops; *cur; cur = next) {
+		gp_babel_nexthop_t *nexthop = *cur;
+		next = &nexthop->next;
+
+		if (!nexthop->neigh) /* local */
+			continue;
+
+		if (!nexthop->neigh->iface) {
+			if (nexthop->metric_seqno.metric != GP_BABEL_INFINITY) {
+				nexthop->metric_seqno.metric = GP_BABEL_INFINITY;
+				nexthop->last_update = gmrf_now(gmrf);
+				nexthop->last_update += GP_BABEL_UPDATE_TIMEOUT(nexthop->interval)*10;
+			}
+
+			continue;
+		}
+
+		if (gmrf_now(gmrf) > nexthop->last_update+GP_BABEL_UPDATE_TIMEOUT(nexthop->interval)*10) {
+			if (nexthop->metric_seqno.metric == GP_BABEL_INFINITY) {
+				*cur = *next;
+				next = cur;
+
+				if (announce->selected == nexthop)
+					announce->selected = NULL;
+
+				gp_babel_neigh_unref(nexthop->neigh);
+
+				free(nexthop);
+			}
+			else {
+				nexthop->metric_seqno.metric = GP_BABEL_INFINITY;
+				nexthop->last_update += GP_BABEL_UPDATE_TIMEOUT(nexthop->interval)*10;
+			}
+		}
+		else if (gmrf_now(gmrf) > nexthop->last_update+GP_BABEL_UPDATE_REQUEST_TIMEOUT(nexthop->interval)*10 && announce->selected == nexthop) {
+			if (!nexthop->requested_update) {
+				gmrf_logf(gmrf, LOG_INFO, "announce about to expire, requesting update");
+				// gp_babel_send_announce_request(nexthop->neigh->iface, nexthop->neigh, announce->node, announce->type, announce->key, false);
+				nexthop->requested_update = true;
+			}
+		}
+	}
+}
+
+static gp_babel_nexthop_t* select_nexthop(gmrf_t *gmrf, const gp_babel_announce_t *announce) {
+	uint16_t ret_metric = GP_BABEL_INFINITY;
+	gp_babel_nexthop_t *ret = NULL;
+
+	gp_babel_nexthop_t *nexthop;
+	for (nexthop = announce->nexthops; nexthop; nexthop = nexthop->next) {
+		if (!nexthop->neigh) /* local */
+			return nexthop;
+
+		if (!gp_babel_is_feasible(announce, nexthop->metric_seqno))
+			continue;
+
+		uint32_t metric = nexthop->metric_seqno.metric + gp_babel_neigh_get_cost(gmrf, nexthop->neigh);
+
+		if (metric < ret_metric) {
+			ret = nexthop;
+			ret_metric = metric;
+		}
+	}
+
+	return ret;
+}
+
+gp_babel_metric_seqno_t get_metric(gmrf_t *gmrf, const gp_babel_announce_t *announce) {
+	if (announce->selected) {
+		uint32_t metric = announce->selected->metric_seqno.metric + gp_babel_neigh_get_cost(gmrf, announce->selected->neigh);
+
+		if (metric < GP_BABEL_INFINITY)
+			return (gp_babel_metric_seqno_t){metric, announce->selected->metric_seqno.seqno};
+	}
+
+	return (gp_babel_metric_seqno_t){GP_BABEL_INFINITY, 0};
+}
+
+void gp_babel_announce_update(gmrf_t *gmrf, gp_babel_announce_t *announce) {
+	maintain_nexthops(gmrf, announce);
+
+	announce->selected = select_nexthop(gmrf, announce);
+	announce->metric = get_metric(gmrf, announce);
+
+	//if (!announce->selected)
+	//	gp_babel_send_seqno_request_for(NULL, announce);
+
+	/* triggered updates */
+	/*int diff =  announce->metric.metric - announce->last_metric;
+
+	if (((announce->last_metric == GP_BABEL_INFINITY) != (announce->metric.metric == GP_BABEL_INFINITY))
+	    || diff <= -1024 || diff >= 384) {
+		gmrf_logf(gmrf, LOG_INFO, "announce metric has changed significantly, sending updates");
+		gp_babel_update_enqueue(&announce->node, announce->type, announce->key, NULL, announce->metric.metric == GP_BABEL_INFINITY);
+	} */
+}
+
+void gp_babel_announce_update_nexthop(gmrf_t *gmrf, gp_babel_announce_t *announce, gp_babel_nexthop_t *nexthop, gp_babel_metric_seqno_t ms, uint16_t interval) {
+	nexthop->metric_seqno = ms;
+	nexthop->interval = interval;
+	nexthop->requested_update = false;
+
+	if (ms.metric != GP_BABEL_INFINITY)
+		nexthop->last_update = gmrf_now(gmrf);
+
+	gp_babel_announce_update(gmrf, announce);
+}
-- 
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