Somewhat hacky implementation of update retransmits

5 files changed, 104 insertions, 16 deletions

diff --git a/ffd/announce.c b/ffd/announce.c
index 00bd78c..491aefd 100644
--- a/ffd/announce.c
+++ b/ffd/announce.c
@@ -123,7 +123,7 @@ static inline void seqno_update(ffd_announce_t *announce) {
 			next = cur;
 
 			fprintf(stderr, "debug: update matches seqno request, forwarding\n");
-			ffd_send_update(NULL, req->neigh, announce, false);
+			ffd_send_update(NULL, req->neigh, announce, true, false);
 			ffd_neigh_unref(req->neigh);
 			free(req);
 		}
@@ -145,7 +145,7 @@ void ffd_announce_update(ffd_announce_t *announce) {
 	if (((announce->last_metric == 0xffff) != (announce->metric.metric == 0xffff))
 	    || diff <= -1024 || diff >= 384) {
 		fprintf(stderr, "info: announce metric has changed significantly, sending updates\n");
-		ffd_send_update(NULL, NULL, announce, false);
+		ffd_send_update(NULL, NULL, announce, announce->metric.metric == 0xffff, false);
 	}
 
 	if (announce->selected)
diff --git a/ffd/ffd.c b/ffd/ffd.c
index 9351476..fd82d0c 100644
--- a/ffd/ffd.c
+++ b/ffd/ffd.c
@@ -52,7 +52,8 @@ static char *mesh = "bat0";
 int sockfd;
 struct timespec now;
 
-static ffd_queue_head *tasks;
+ffd_queue_head *tasks = NULL;
+ffd_queue_head *retransmits = NULL;
 
 ffd_node_id_t self;
 ffd_iface_t *iface_list = NULL;
@@ -358,13 +359,13 @@ static void handle_tlv_announce_req(const ffd_tlv_announce_req_t *tlv_req, size_
 	fprintf(stderr, "debug: received announce request\n");
 
 	if (ffd_is_node_id_unspec(&tlv_req->node)) {
-		ffd_send_update(NULL, get_tlv_neigh(arg), NULL, tlv_req->flags & FFD_UPDATE_WITH_DATA);
+		ffd_send_update(NULL, get_tlv_neigh(arg), NULL, false, tlv_req->flags & FFD_UPDATE_WITH_DATA);
 	}
 	else {
 		ffd_announce_t *announce = ffd_announce_find(&tlv_req->node, ntohs(tlv_req->type), ntohs(tlv_req->key));
 
 		if (announce)
-			ffd_send_update(NULL, get_tlv_neigh(arg), announce, tlv_req->flags & FFD_UPDATE_WITH_DATA);
+			ffd_send_update(NULL, get_tlv_neigh(arg), announce, false, tlv_req->flags & FFD_UPDATE_WITH_DATA);
 		else
 			ffd_send_retract(get_tlv_neigh(arg), tlv_req->node, ntohs(tlv_req->type), ntohs(tlv_req->key));
 	}
@@ -397,14 +398,14 @@ static void handle_tlv_seqno_req(const ffd_tlv_seqno_req_t *tlv_req, size_t len,
 
 	if ((int16_t)(seqno-announce->selected->metric_seqno.seqno) <= 0) {
 		fprintf(stderr, "debug: received seqno request, seqno already ok\n");
-		ffd_send_update(NULL, neigh, announce, false);
+		ffd_send_update(NULL, neigh, announce, true, false);
 		return;
 	}
 
 	if (!announce->selected->neigh) {
 		fprintf(stderr, "debug: received seqno request, incrementing seqno\n");
 		announce->selected->metric_seqno.seqno++;
-		ffd_send_update(NULL, neigh, announce, false);
+		ffd_send_update(NULL, neigh, announce, true, false);
 		return;
 	}
 
@@ -494,7 +495,7 @@ static void send_updates(void) {
 
 	ffd_iface_t *iface;
 	for (iface = iface_list; iface; iface = iface->next) {
-		ffd_send_update(iface, NULL, NULL, false);
+		ffd_send_update(iface, NULL, NULL, false, false);
 	}
 }
 
@@ -591,6 +592,16 @@ static void register_periodic_tasks(void) {
 }
 
 
+static inline int timeout_min(int a, int b) {
+	if (a < 0)
+		return b;
+	else if (b < 0)
+		return a;
+	else
+		return min(a, b);
+}
+
+
 int main() {
 	if (!check_config())
 		return 1;
@@ -606,10 +617,11 @@ int main() {
 
 	while (true) {
 		ffd_queue_run(&tasks);
+		ffd_queue_run(&retransmits);
 
 		struct pollfd fds[1];
 
-		int timeout = 10*ffd_queue_timeout(&tasks);
+		int timeout = 10*timeout_min(ffd_queue_timeout(&tasks), ffd_queue_timeout(&retransmits));
 		if (timeout < 0)
 			timeout = -1;
 
diff --git a/ffd/ffd.h b/ffd/ffd.h
index edba710..4bb7038 100644
--- a/ffd/ffd.h
+++ b/ffd/ffd.h
@@ -207,7 +207,7 @@ void ffd_announce_seqno_request_free_list(ffd_announce_t *announce);
 
 void ffd_send_ack(ffd_neigh_t *neigh, uint16_t nonce);
 void ffd_send_hellos(void);
-void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool with_data);
+void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool urgent, bool with_data);
 void ffd_send_retract(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);
 void ffd_send_seqno_request(ffd_neigh_t *neigh, ffd_announce_t *announce, uint16_t seqno);
diff --git a/ffd/queue.h b/ffd/queue.h
index 9fae53d..4674481 100644
--- a/ffd/queue.h
+++ b/ffd/queue.h
@@ -40,6 +40,10 @@ typedef struct _ffd_queue_head {
 } ffd_queue_head;
 
 
+extern ffd_queue_head *tasks;
+extern ffd_queue_head *retransmits;
+
+
 void ffd_queue_put(ffd_queue_head **queue, ffd_queue_cb cb, const struct timespec *timeout, void *arg);
 
 
diff --git a/ffd/send.c b/ffd/send.c
index ebda0de..936e1fb 100644
--- a/ffd/send.c
+++ b/ffd/send.c
@@ -27,6 +27,7 @@
 #include "ffd.h"
 #include "neigh.h"
 #include "packet.h"
+#include "queue.h"
 #include "tlv.h"
 #include "tlv_types.h"
 
@@ -72,6 +73,7 @@ static bool send_eth(const eth_addr_t *addr, unsigned ifindex, const void *buf,
 	return true;
 }
 
+
 static inline bool send_neigh(const ffd_neigh_t *neigh, const ffd_packet_t *packet) {
 	if (!neigh->iface)
 		return false;
@@ -84,8 +86,12 @@ static inline bool send_neigh(const ffd_neigh_t *neigh, const ffd_packet_t *pack
 	return true;
 }
 
+static inline bool send_ifindex(unsigned ifindex, const ffd_packet_t *packet) {
+	return send_eth(&ffd_addr, ifindex, packet, sizeof(ffd_packet_t)+ntohs(packet->len));
+}
+
 static inline bool send_iface(const ffd_iface_t *iface, const ffd_packet_t *packet) {
-	if (!send_eth(&ffd_addr, iface->ifindex, packet, sizeof(ffd_packet_t)+ntohs(packet->len))) {
+	if (!send_ifindex(iface->ifindex, packet)) {
 		fprintf(stderr, "send_eth: %m\n");
 		return false;
 	}
@@ -108,6 +114,54 @@ static inline void send_any(const ffd_iface_t *iface, const ffd_neigh_t *neigh,
 		send_broadcast(packet);
 }
 
+
+typedef struct _retransmit_arg {
+	unsigned iface;
+	ffd_neigh_t *neigh;
+	ffd_packet_t *packet;
+
+	unsigned ref;
+} retransmit_arg;
+
+static void retransmit_cb(const struct timespec *timeout, void *argp) {
+	retransmit_arg *arg = argp;
+
+	fprintf(stderr, "debug: doing retransmit\n");
+
+	if (arg->neigh)
+		send_neigh(arg->neigh, arg->packet);
+	else if(arg->iface)
+		send_ifindex(arg->iface, arg->packet);
+	else
+		send_broadcast(arg->packet);
+
+	if (!--arg->ref) {
+		if (arg->neigh)
+			ffd_neigh_unref(arg->neigh);
+
+		free(arg->packet);
+		free(arg);
+	}
+}
+
+static void send_retransmit(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_packet_t *packet) {
+	if (neigh)
+		ffd_neigh_ref(neigh);
+
+	retransmit_arg *arg = malloc(sizeof(retransmit_arg));
+	arg->iface = iface ? iface->ifindex : 0;
+	arg->neigh = neigh;
+	arg->packet = packet;
+	arg->ref = 5;
+
+	ffd_queue_put_delayed(&retransmits, retransmit_cb, &now, 100, arg);
+	ffd_queue_put_delayed(&retransmits, retransmit_cb, &now, 75, arg);
+	ffd_queue_put_delayed(&retransmits, retransmit_cb, &now, 50, arg);
+	ffd_queue_put_delayed(&retransmits, retransmit_cb, &now, 25, arg);
+	ffd_queue_put_delayed(&retransmits, retransmit_cb, &now, 0, arg);
+}
+
+
 void ffd_send_ack(ffd_neigh_t *neigh, uint16_t nonce) {
 	ffd_packet_t *packet = alloca(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
 
@@ -223,8 +277,12 @@ static bool add_update(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node
 	return true;
 }
 
-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);
+void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool urgent, bool with_data) {
+	ffd_packet_t *packet;
+	if (urgent)
+		packet = malloc(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
+	else
+		packet = alloca(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
 
 	packet->version_magic = htons(FFD_VERSION_MAGIC);
 	packet->len = 0;
@@ -238,7 +296,13 @@ void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *ann
 		ffd_announce_t *a;
 		for (a = announce_list; a; a = a->next) {
 			if (!add_update(packet, FFD_PACKET_MAX, &node_id, a, with_data, iface || neigh)) {
-				send_any(iface, neigh, packet);
+				if (urgent) {
+					send_retransmit(iface, neigh, packet);
+					packet = malloc(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
+				}
+				else {
+					send_any(iface, neigh, packet);
+				}
 
 				node_id = FFD_NODE_ID_UNSPEC;
 				packet->len = 0;
@@ -251,8 +315,16 @@ void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *ann
 		}
 	}
 
-	if (packet->len)
-		send_any(iface, neigh, packet);
+	if (urgent) {
+		if (packet->len)
+			send_retransmit(iface, neigh, packet);
+		else
+			free(packet);
+	}
+	else {
+		if (packet->len)
+			send_any(iface, neigh, packet);
+	}
 }
 
 void ffd_send_retract(ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key) {