Lots of update handling

6 files changed, 179 insertions, 39 deletions

diff --git a/ffd/announce.c b/ffd/announce.c
index eade2f1..4e8e07a 100644
--- a/ffd/announce.c
+++ b/ffd/announce.c
@@ -25,35 +25,37 @@
 
 
 #include "ffd.h"
+#include "neigh.h"
 
 
-static bool is_feasable(const ffd_announce_t *announce, const ffd_nexthop_t *nexthop) {
-	if (FFD_IS_INFINITY(announce->feasability_distance))
+bool ffd_is_feasable(const ffd_announce_t *announce, ffd_metric_seqno_t ms) {
+	if (FFD_IS_INFINITY(ms) || FFD_IS_INFINITY(announce->feasability_distance))
 		return true;
 
-	int16_t seqno_diff = nexthop->metric_seqno.seqno - announce->feasability_distance.seqno;
+	int16_t seqno_diff = ms.seqno - announce->feasability_distance.seqno;
 
 	if (seqno_diff < 0)
 		return true;
-	if (seqno_diff == 0 && nexthop->metric_seqno.metric < announce->feasability_distance.metric)
+	if (seqno_diff == 0 && ms.metric < announce->feasability_distance.metric)
 		return true;
 
 	return false;
 }
 
 static ffd_nexthop_t* select_nexthop(const ffd_announce_t *announce) {
+	uint16_t ret_metric = 0xffff;
 	ffd_nexthop_t *ret = NULL;
 
 	ffd_nexthop_t *nexthop;
-	for (nexthop = announce->nexthop_list->next; nexthop; nexthop = nexthop->next) {
-		if (is_feasable(announce, nexthop))
+	for (nexthop = announce->nexthop_list; nexthop; nexthop = nexthop->next) {
+		if (!ffd_is_feasable(announce, nexthop->metric_seqno))
 			continue;
 
-		int16_t seqno_diff = nexthop->metric_seqno.seqno - ret->metric_seqno.seqno;
+		uint32_t metric = nexthop->metric_seqno.metric + ffd_neigh_get_cost(nexthop->neigh);
 
-		if (nexthop->metric_seqno.metric < ret->metric_seqno.metric
-		    || (nexthop->metric_seqno.metric == ret->metric_seqno.metric && seqno_diff < 0)) {
+		if (metric < ret_metric) {
 			ret = nexthop;
+			ret_metric = metric;
 		}
 	}
 
@@ -61,20 +63,24 @@ static ffd_nexthop_t* select_nexthop(const ffd_announce_t *announce) {
 }
 
 ffd_metric_seqno_t ffd_announce_get_metric(const ffd_announce_t *announce) {
-	ffd_nexthop_t *nexthop = select_nexthop(announce);
+	if (announce->selected) {
+		uint32_t metric = announce->selected->metric_seqno.metric + ffd_neigh_get_cost(announce->selected->neigh);
 
-	if (nexthop)
-		return nexthop->metric_seqno;
-	else
-		return (ffd_metric_seqno_t){0xffff, 0};
+		if (metric < 0xffff)
+			return (ffd_metric_seqno_t){metric, announce->selected->metric_seqno.seqno};
+	}
+
+	return (ffd_metric_seqno_t){0xffff, 0};
 }
 
+void ffd_announce_update_nexthop(ffd_announce_t *announce) {
+	announce->selected = select_nexthop(announce);
+}
 
-ffd_announce_t* ffd_announce_new(size_t len) {
-	ffd_announce_t *a = calloc(1, sizeof(ffd_announce_t)+len);
+ffd_announce_t* ffd_announce_new(void) {
+	ffd_announce_t *a = calloc(1, sizeof(ffd_announce_t));
 
-	a->len = len;
-	a->feasability_distance = (ffd_metric_seqno_t){0xffff, 0};
+	a->feasability_distance.metric = 0xffff;
 
 	a->next = announce_list;
 	announce_list = a;
diff --git a/ffd/ffd.c b/ffd/ffd.c
index 3512906..5f17446 100644
--- a/ffd/ffd.c
+++ b/ffd/ffd.c
@@ -98,9 +98,8 @@ static bool init_self(void) {
 	announce->node = self;
 	announce->type = 1;
 	announce->key = 1337;
-	announce->interval = 6000;
 
-	announce->nexthop_list = calloc(1, sizeof(ffd_nexthop_t));
+	announce->nexthop_list = announce->selected = calloc(1, sizeof(ffd_nexthop_t));
 
 	return true;
 }
@@ -273,13 +272,107 @@ static void handle_tlv_node_id(const ffd_tlv_node_id_t *tlv_node_id, size_t len,
 	arg->node_id = tlv_node_id->id;
 }
 
-static void handle_tlv_update(const ffd_tlv_node_id_t *tlv_node_id, size_t len, handle_tlv_arg_t *arg) {
+static ffd_announce_t* get_announce(const ffd_node_id_t *node, uint16_t type, uint16_t key) {
+	ffd_announce_t *announce;
+	for (announce = announce_list; announce; announce = announce->next) {
+		if (ffd_are_node_ids_equal(&announce->node, node)
+		    && announce->type == type
+		    && announce->key == key)
+			return announce;
+	}
+
+	/* not found */
+	announce = ffd_announce_new();
+	announce->node = *node;
+	announce->type = type;
+	announce->key = key;
+
+	return announce;
+}
+
+static ffd_nexthop_t* find_nexthop(const ffd_announce_t *announce, ffd_neigh_t *neigh) {
+	ffd_nexthop_t *nexthop;
+	for (nexthop = announce->nexthop_list; nexthop; nexthop = nexthop->next) {
+		if (nexthop->neigh == neigh)
+			return nexthop;
+	}
+
+	return NULL;
+}
+
+static ffd_nexthop_t* new_nexthop(ffd_announce_t *announce, ffd_neigh_t *neigh) {
+	ffd_nexthop_t *nexthop = calloc(1, sizeof(ffd_nexthop_t));
+	nexthop->neigh = neigh;
+
+	nexthop->next = announce->nexthop_list;
+	announce->nexthop_list = nexthop;
+
+	return nexthop;
+}
+
+static void handle_tlv_update(const ffd_tlv_update_t *tlv_update, size_t len, handle_tlv_arg_t *arg) {
 	if (len < sizeof(ffd_tlv_update_t)) {
 		fprintf(stderr, "warn: received short update TLV.\n");
 		return;
 	}
 
+	if (ffd_is_node_id_unspec(&arg->node_id)) {
+		fprintf(stderr, "warn: received update TLV without node id TLV.\n");
+		return;
+	}
+
+	if (ffd_are_node_ids_equal(&arg->node_id, &self)) {
+		fprintf(stderr, "debug: update source is myself.\n");
+		return;
+	}
+
 	fprintf(stderr, "debug: update received from %04x%04x.\n", ntohl(*(uint32_t*)arg->node_id.id), ntohl(*(uint32_t*)(arg->node_id.id+4)));
+
+	ffd_announce_t *announce = get_announce(&arg->node_id, ntohs(tlv_update->type), ntohs(tlv_update->key));
+	ffd_metric_seqno_t ms = { ntohs(tlv_update->metric), ntohs(tlv_update->seqno) };
+	bool feasable = ffd_is_feasable(announce, ms);
+
+	ffd_neigh_t *neigh = get_tlv_neigh(arg);
+	ffd_nexthop_t *nexthop = find_nexthop(announce, neigh);
+
+	if (!nexthop) {
+		if (!feasable || tlv_update->metric == 0xffff /* no need to ntohs */)
+			return;
+
+		nexthop = new_nexthop(announce, neigh);
+	}
+	else {
+		if (!feasable && nexthop == announce->selected)
+			return;
+	}
+
+	nexthop->metric_seqno.metric = ntohs(tlv_update->metric);
+	nexthop->metric_seqno.seqno = ntohs(tlv_update->seqno);
+	nexthop->interval = ntohs(tlv_update->interval);
+
+	fprintf(stderr, "debug: the update was accepted.\n");
+
+	if (nexthop->metric_seqno.metric == 0xffff)
+		return;
+
+	/* only update the timestamp for finite metrics */
+	nexthop->last_update = now;
+
+	if ((tlv_update->flags & FFD_UPDATE_WITH_DATA) && !announce->data) {
+		if (len > sizeof(ffd_tlv_update_t)) {
+			announce->len = len - sizeof(ffd_tlv_update_t);
+			announce->data = malloc(announce->len);
+			memcpy(announce->data, tlv_update->data, announce->len);
+		}
+		else {
+			announce->len = 0xff;
+
+			/* request data */
+			ffd_send_announce_request(arg->iface, neigh, announce->node, announce->type, announce->key, true);
+		}
+	}
+
+	ffd_announce_update_nexthop(announce);
 }
 
 static void handle_tlv_announce_req(const ffd_tlv_announce_req_t *tlv_req, size_t len, handle_tlv_arg_t *arg) {
@@ -294,7 +387,7 @@ static void handle_tlv_announce_req(const ffd_tlv_announce_req_t *tlv_req, size_
 		announce = NULL;
 	}
 
-	ffd_send_update(arg->iface, get_tlv_neigh(arg), announce);
+	ffd_send_update(arg->iface, get_tlv_neigh(arg), announce, tlv_req->flags & FFD_UPDATE_WITH_DATA);
 }
 
 static void handle_tlv(ffd_tlv_type_t type, const void *data, size_t len, void *arg) {
diff --git a/ffd/ffd.h b/ffd/ffd.h
index cf9d59c..e0f1954 100644
--- a/ffd/ffd.h
+++ b/ffd/ffd.h
@@ -40,6 +40,11 @@
 #define FFD_HELLO_INTERVAL 400
 #define FFD_IHU_INTERVAL (3*FFD_HELLO_INTERVAL)
 
+#define FFD_UPDATE_INTERVAL 400
+
+
+#define FFD_UPDATE_WITH_DATA 0x01
+
 
 typedef struct __attribute__((packed)) _ffd_node_id_t {
 	uint8_t id[8];
@@ -77,9 +82,11 @@ typedef struct _ffd_metric_seqno_t {
 typedef struct _ffd_nexthop_t {
 	struct _ffd_nexthop_t *next;
 
-	struct timespec last_update;
-	eth_addr_t addr;
+	struct _ffd_neigh_t *neigh;
 	ffd_metric_seqno_t metric_seqno;
+
+	struct timespec last_update;
+	uint16_t interval;
 } ffd_nexthop_t;
 
 typedef struct _ffd_announce_t {
@@ -88,21 +95,22 @@ typedef struct _ffd_announce_t {
 	ffd_node_id_t node;
 	uint16_t type;
 	uint16_t key;
-	uint16_t interval;
-
-	uint8_t len;
 
 	ffd_metric_seqno_t feasability_distance;
 
 	ffd_nexthop_t *selected;
 	ffd_nexthop_t *nexthop_list;
 
-	uint8_t data[];
+	/* an incomplete announcement is specified by a len value of 0xff with NULL data */
+	uint8_t len;
+	uint8_t *data;
 } ffd_announce_t;
 
 typedef struct _ffd_neigh_t {
 	struct _ffd_neigh_t *next;
 
+	/* for actual routing, we'd also have to link back to the iface
+	   this neighbour belongs to */
 	eth_addr_t addr;
 
 	uint16_t hello_log;
@@ -130,6 +138,8 @@ typedef struct _ffd_iface_t {
 
 extern const eth_addr_t ffd_addr;
 
+extern ffd_node_id_t self;
+
 extern ffd_iface_t *iface_list;
 extern ffd_announce_t *announce_list;
 
@@ -137,11 +147,13 @@ extern int sockfd;
 extern struct timespec now;
 
 
+bool ffd_is_feasable(const ffd_announce_t *announce, ffd_metric_seqno_t ms);
 ffd_metric_seqno_t ffd_announce_get_metric(const ffd_announce_t *announce);
-ffd_announce_t* ffd_announce_new(size_t len);
+void ffd_announce_update_nexthop(ffd_announce_t *announce);
+ffd_announce_t* ffd_announce_new(void);
 
 void ffd_send_hellos(void);
-void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, const ffd_announce_t *announce);
-void ffd_send_announce_request(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key);
+void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool with_data);
+void ffd_send_announce_request(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key, bool with_data);
 
 #endif /* _FFD_FFD_H_ */
diff --git a/ffd/neigh.c b/ffd/neigh.c
index 9788d3f..02a3318 100644
--- a/ffd/neigh.c
+++ b/ffd/neigh.c
@@ -64,6 +64,9 @@ uint16_t ffd_neigh_get_rxcost(const ffd_neigh_t *neigh) {
 }
 
 uint16_t ffd_neigh_get_cost(const ffd_neigh_t *neigh) {
+	if (!neigh) /* self */
+		return 0;
+
 	uint16_t txcost = neigh->txcost;
 	if (txcost < 256)
 		txcost = 256;
@@ -77,5 +80,5 @@ uint16_t ffd_neigh_get_cost(const ffd_neigh_t *neigh) {
 }
 
 void ffd_neigh_reset(ffd_iface_t *iface, ffd_neigh_t *neigh) {
-	ffd_send_announce_request(iface, neigh, FFD_NODE_ID_UNSPEC, 0, 0);
+	ffd_send_announce_request(iface, neigh, FFD_NODE_ID_UNSPEC, 0, 0, true /* XXX change this later */);
 }
diff --git a/ffd/send.c b/ffd/send.c
index fe5035d..48c44fc 100644
--- a/ffd/send.c
+++ b/ffd/send.c
@@ -126,7 +126,12 @@ static bool add_node_id(ffd_packet_t *packet, size_t max_len, ffd_node_id_t node
 	return true;
 }
 
-static bool add_update(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node_id, const ffd_announce_t *announce) {
+static bool add_update(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node_id, ffd_announce_t *announce, bool with_data) {
+	if (announce->len && !announce->data) {
+		/* incomplete announce, handle like non-existant announce */
+		return true;
+	}
+
 	uint16_t len = packet->len;
 
 	if (!node_id || !ffd_are_node_ids_equal(node_id, &announce->node)) {
@@ -145,32 +150,42 @@ static bool add_update(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node
 
 	ffd_metric_seqno_t metric = ffd_announce_get_metric(announce);
 
-	update->interval = htons(announce->interval);
+	update->flags = 0;
+	update->reserved = 0;
+	update->interval = htons(FFD_UPDATE_INTERVAL);
 	update->seqno = htons(metric.seqno);
 	update->metric = htons(metric.metric);
 	update->type = htons(announce->type);
 	update->key = htons(announce->key);
 
-	memcpy(update->data, announce->data, announce->len);
+	if (announce->len) {
+		update->flags |= FFD_UPDATE_WITH_DATA;
+
+		if (with_data) {
+			memcpy(update->data, announce->data, announce->len);
+		}
+	}
+
+	announce->feasability_distance = metric;
 
 	return true;
 }
 
-void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, const ffd_announce_t *announce) {
+void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool with_data) {
 	ffd_packet_t *packet = alloca(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
 
 	packet->version_magic = htons(FFD_VERSION_MAGIC);
 	packet->len = 0;
 
 	if (announce) {
-		add_update(packet, FFD_PACKET_MAX, NULL, announce);
+		add_update(packet, FFD_PACKET_MAX, NULL, announce, with_data);
 	}
 	else {
 		ffd_node_id_t node_id = FFD_NODE_ID_UNSPEC;
 
 		ffd_announce_t *a;
 		for (a = announce_list; a; a = a->next) {
-			if (!add_update(packet, FFD_PACKET_MAX, &node_id, a)) {
+			if (!add_update(packet, FFD_PACKET_MAX, &node_id, a, with_data)) {
 				if (!send_eth(&ffd_addr, iface->ifindex, packet, sizeof(ffd_packet_t)+ntohs(packet->len)))
 					fprintf(stderr, "send_eth: %m\n");
 
@@ -186,7 +201,7 @@ void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, const ffd_announce_
 	}
 }
 
-void ffd_send_announce_request(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key) {
+void ffd_send_announce_request(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key, bool with_data) {
 	ffd_packet_t *packet = alloca(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
 
 	packet->version_magic = htons(FFD_VERSION_MAGIC);
@@ -197,9 +212,14 @@ void ffd_send_announce_request(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_node_
 		return;
 
 	req->node = node;
+	req->flags = 0;
+	req->reserved = 0;
 	req->type = htons(type);
 	req->key = htons(key);
 
+	if (with_data)
+		req->flags |= FFD_UPDATE_WITH_DATA;
+
 	if (!send_eth(&ffd_addr, iface->ifindex, packet, sizeof(ffd_packet_t)+ntohs(packet->len)))
 		fprintf(stderr, "send_eth: %m\n");
 }
diff --git a/ffd/tlv_types.h b/ffd/tlv_types.h
index a37e095..afe793a 100644
--- a/ffd/tlv_types.h
+++ b/ffd/tlv_types.h
@@ -49,6 +49,8 @@ typedef struct __attribute__((packed)) _ffd_tlv_node_id_t {
 } ffd_tlv_node_id_t;
 
 typedef struct __attribute__((packed)) _ffd_tlv_update_t {
+	uint8_t flags;
+	uint8_t reserved;
 	uint16_t interval;
 	uint16_t seqno;
 	uint16_t metric;
@@ -59,12 +61,16 @@ typedef struct __attribute__((packed)) _ffd_tlv_update_t {
 
 typedef struct __attribute__((packed)) _ffd_tlv_announce_req_t {
 	ffd_node_id_t node;
+	uint8_t flags;
+	uint8_t reserved;
 	uint16_t type;
 	uint16_t key;
 } ffd_tlv_announce_req_t;
 
 typedef struct __attribute__((packed)) _ffd_tlv_seqno_req_t {
 	ffd_node_id_t node;
+	uint8_t flags;
+	uint8_t reserved;
 	uint16_t type;
 	uint16_t key;
 	uint16_t seqno;