Add nexthop data structure and receive updates

src/announce.c

@@ -25,6 +25,7 @@
 
 
 #include "babel.h"
+#include "neigh.h"
 
 #include <stdlib.h>
 
@@ -68,3 +69,25 @@ gp_babel_announce_t* gp_babel_announce_get(gmrf_t *gmrf, gmrf_context_t *ctx, co
 void gp_babel_announce_free(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_announce_t *announce) {
 	free(announce);
 }
+
+gp_babel_nexthop_t* gp_babel_announce_nexthop_find(const gp_babel_announce_t *announce, gp_babel_neigh_t *neigh) {
+	gp_babel_nexthop_t *nexthop;
+	for (nexthop = announce->nexthops; nexthop; nexthop = nexthop->next) {
+		if (nexthop->neigh == neigh)
+			return nexthop;
+	}
+
+	return NULL;
+}
+
+gp_babel_nexthop_t* gp_babel_announce_nexthop_new(gp_babel_announce_t *announce, gp_babel_neigh_t *neigh) {
+	gp_babel_nexthop_t *nexthop = calloc(1, sizeof(gp_babel_nexthop_t));
+	nexthop->neigh = neigh;
+
+	nexthop->next = announce->nexthops;
+	announce->nexthops = nexthop;
+
+	gp_babel_neigh_ref(neigh);
+
+	return nexthop;
+}

src/babel.h

@@ -94,16 +94,34 @@ struct gp_babel_announce {
 	uint16_t last_metric;
 	gp_babel_metric_seqno_t feasibility_distance;
 
+	gp_babel_nexthop_t *selected;
+	gp_babel_nexthop_t *nexthops;
+
 	/* an incomplete announcement is specified by a len value of 0xff with NULL data */
 	uint8_t len;
 	uint8_t *data;
 };
 
+struct gp_babel_nexthop {
+	gp_babel_nexthop_t *next;
+
+	gp_babel_neigh_t *neigh;
+	gp_babel_metric_seqno_t metric_seqno;
+
+	gmrf_time_t last_update;
+	uint16_t interval;
+	bool requested_update;
+};
+
 
 static inline bool gp_babel_node_id_equal(const gp_babel_node_id_t *id1, const gp_babel_node_id_t *id2) {
 	return (memcmp(id1->id, id2->id, GP_BABEL_NODE_ID_LENGTH) == 0);
 }
 
+static inline bool gp_babel_node_id_is_unspec(const gp_babel_node_id_t *id) {
+	return gp_babel_node_id_equal(id, &gp_babel_node_id_unspec);
+};
+
 static inline gp_babel_iface_t* gp_babel_get_iface(gmrf_context_t *ctx, gmrf_iface_t *gmrf_iface) {
 	gp_babel_iface_t *iface;
 	for (iface = ctx->interfaces; iface; iface = iface->next) {
@@ -153,4 +171,7 @@ gp_babel_announce_t* gp_babel_announce_find(gmrf_t *gmrf, gmrf_context_t *ctx, c
 gp_babel_announce_t* gp_babel_announce_get(gmrf_t *gmrf, gmrf_context_t *ctx, const gp_babel_node_id_t *node, uint16_t type, uint16_t key);
 void gp_babel_announce_free(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_announce_t *announce);
 
+gp_babel_nexthop_t* gp_babel_announce_nexthop_new(gp_babel_announce_t *announce, gp_babel_neigh_t *neigh);
+gp_babel_nexthop_t* gp_babel_announce_nexthop_find(const gp_babel_announce_t *announce, gp_babel_neigh_t *neigh);
+
 #endif /* _GMRF_PROTO_BABEL_BABEL_H_ */

src/tlv_types.c

@@ -145,6 +145,76 @@ static void handle_tlv_node_id(gmrf_t *gmrf, gmrf_context_t *ctx, const gp_babel
 	arg->node_id = tlv_node_id->id;
 }
 
+static void handle_tlv_update(gmrf_t *gmrf, gmrf_context_t *ctx, const gp_babel_tlv_update_t *tlv_update, size_t len, handle_tlv_arg_t *arg) {
+	if (len < sizeof(gp_babel_tlv_update_t)) {
+		gmrf_logf(gmrf, LOG_WARNING, "received short update TLV.");
+		return;
+	}
+
+	if (gp_babel_node_id_is_unspec(&arg->node_id)) {
+		gmrf_logf(gmrf, LOG_WARNING, "received update TLV without node id TLV.");
+		return;
+	}
+
+	if (gp_babel_node_id_equal(&arg->node_id, &ctx->self)) {
+		gmrf_logf(gmrf, LOG_DEBUG, "update source is myself.");
+		return;
+	}
+
+	gp_babel_announce_t *announce = gp_babel_announce_get(gmrf, ctx, &arg->node_id, ntohs(tlv_update->type), ntohs(tlv_update->key));
+	gp_babel_metric_seqno_t ms = { ntohs(tlv_update->metric), ntohs(tlv_update->seqno) };
+	bool feasible = gp_babel_is_feasible(announce, ms);
+
+	gp_babel_neigh_t *neigh = get_tlv_neigh(arg);
+	gp_babel_nexthop_t *nexthop = gp_babel_announce_nexthop_find(announce, neigh);
+
+	gmrf_logf(gmrf, LOG_DEBUG, "update received from %04x%04x, metric %u, seqno %04x.",
+		  ntohl(*(uint32_t*)arg->node_id.id), ntohl(*(uint32_t*)(arg->node_id.id+4)),
+		  ms.metric, ms.seqno);
+	gmrf_logf(gmrf, LOG_DEBUG, "the update is %sfeasible and there is %s nexthop.", feasible ? "" : "not ", nexthop ? "a" : "no");
+
+	if (!nexthop) {
+		if (feasible && tlv_update->metric != GP_BABEL_INFINITY /* no need to ntohs */)
+			nexthop = gp_babel_announce_nexthop_new(announce, neigh);
+	}
+	else {
+		if (!feasible && nexthop == announce->selected) {
+			gmrf_logf(gmrf, LOG_DEBUG, "need new seqno");
+			// gp_babel_send_seqno_request_for(neigh, announce);
+			nexthop = NULL;
+		}
+	}
+
+	if (!feasible && nexthop && nexthop != announce->selected) {
+		if (ms.metric + gp_babel_neigh_get_cost(gmrf, neigh) < announce->metric.metric) {
+			gmrf_logf(gmrf, LOG_DEBUG, "need new seqno");
+			// gp_babel_send_seqno_request_for(neigh, announce);
+		}
+	}
+
+	if (!announce->data) {
+		if (len > sizeof(gp_babel_tlv_update_t)) {
+			announce->len = len - sizeof(gp_babel_tlv_update_t);
+			announce->data = malloc(announce->len);
+			memcpy(announce->data, tlv_update->data, announce->len);
+		}
+		else {
+			announce->len = 0xff;
+
+			/* request data */
+			//if (nexthop)
+			//	gp_babel_send_announce_request(arg->iface, neigh, announce->node, announce->type, announce->key, true);
+		}
+	}
+
+	if (!nexthop)
+		return;
+
+	gmrf_logf(gmrf, LOG_DEBUG, "the update was accepted.");
+
+	//gp_babel_announce_update_nexthop(announce, nexthop, ms, ntohs(tlv_update->interval));
+}
+
 static void handle_tlv(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_tlv_type_t type, const void *data, size_t len, void *arg) {
 	handle_tlv_arg_t *tlv_arg = arg;
 
@@ -169,6 +239,10 @@ static void handle_tlv(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_tlv_type_t ty
 		handle_tlv_node_id(gmrf, ctx, data, len, tlv_arg);
 		return;
 
+	case TLV_UPDATE:
+		handle_tlv_update(gmrf, ctx, data, len, tlv_arg);
+		return;
+
 	default:
 		gmrf_logf(gmrf, LOG_DEBUG, "received unknown TLV %u on %s.", type, gmrf_iface_get_name(gmrf, tlv_arg->iface->gmrf_iface));
 		return;

src/types.h

@@ -48,6 +48,7 @@ typedef struct gp_babel_metric_seqno {
 typedef struct gp_babel_iface gp_babel_iface_t;
 typedef struct gp_babel_neigh gp_babel_neigh_t;
 typedef struct gp_babel_announce gp_babel_announce_t;
+typedef struct gp_babel_nexthop gp_babel_nexthop_t;
 
 typedef struct gp_babel_packet gp_babel_packet_t;
 typedef struct gp_babel_packet_buf gp_babel_packet_buf_t;