Simplify urgent update resend setup code

This reverts commit 4a40b6246a.

ffd/CMakeLists.txt

@@ -1,12 +1,15 @@
 include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${FFD_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR})
 
 add_executable(ffd
+  ack.c
   announce.c
   ffd.c
   neigh.c
   netif.c
+  queue.c
   send.c
   tlv.c
+  update.c
   util.c
 )
 target_link_libraries(ffd rt)

ffd/ack.c

@@ -0,0 +1,91 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "ffd.h"
+#include "queue.h"
+
+
+static uint8_t acks[1 << 13] = {};
+static ffd_queue_t *ack_requests = NULL;
+static uint16_t nonce = 0;
+
+
+#define SET_ACK(n) do {acks[n >> 3] |= 1 << (n & 7);} while(0)
+#define UNSET_ACK(n) do {acks[n >> 3] &= ~(1 << (n & 7));} while(0)
+#define GET_ACK(n) ((acks[n >> 3] & (1 << (n & 7))) != 0)
+
+
+typedef struct _ack_arg_t {
+	void (*cb)(uint16_t nonce, void *arg);
+	void (*free)(uint16_t nonce, void *arg);
+	void *arg;
+
+	uint16_t nonce;
+	unsigned interval;
+	unsigned retries;
+} ack_arg_t;
+
+
+void ffd_ack_handle(uint16_t n) {
+	SET_ACK(n);
+}
+
+static void ack_resend(const struct timespec *timeout, void *argp) {
+	ack_arg_t *arg = argp;
+
+	if (GET_ACK(arg->nonce) || !(--arg->retries)) {
+		arg->free(arg->nonce, arg->arg);
+		free(arg);
+		return;
+	}
+
+	arg->cb(arg->nonce, arg->arg);
+
+	ffd_queue_put_delayed(&ack_requests, ack_resend, timeout, arg->interval, arg);
+}
+
+void ffd_ack_request(void (*cb)(uint16_t nonce, void *arg), void (*free_cb)(uint16_t nonce, void *arg), unsigned interval, unsigned retries, void *arg) {
+	UNSET_ACK(nonce);
+	cb(nonce, arg);
+
+	ack_arg_t *ack_arg = malloc(sizeof(ack_arg_t));
+	ack_arg->cb = cb;
+	ack_arg->free = free_cb;
+	ack_arg->arg = arg;
+	ack_arg->nonce = nonce++;
+	ack_arg->interval = interval;
+	ack_arg->retries = retries;
+
+	ffd_queue_put_delayed(&ack_requests, ack_resend, &now, interval, ack_arg);
+}
+
+int ffd_ack_timeout(void) {
+	return ffd_queue_timeout(&ack_requests);
+}
+
+void ffd_ack_run(void) {
+	ffd_queue_run(&ack_requests);
+}

ffd/announce.c

@@ -26,6 +26,7 @@
 
 #include "ffd.h"
 #include "neigh.h"
+#include "send.h"
 
 #include <stdio.h>
 
@@ -110,6 +111,26 @@ ffd_metric_seqno_t get_metric(const ffd_announce_t *announce) {
 	return (ffd_metric_seqno_t){0xffff, 0};
 }
 
+static inline void seqno_update(ffd_announce_t *announce) {
+	ffd_seqno_req_t **cur, **next;
+	for (cur = &announce->seqno_req_list; *cur; cur = next) {
+		ffd_seqno_req_t *req = *cur;
+		next = &req->next;
+
+		int16_t diff = announce->selected->metric_seqno.seqno - req->seqno;
+
+		if (diff >= 0) {
+			*cur = *next;
+			next = cur;
+
+			fprintf(stderr, "debug: update matches seqno request, forwarding\n");
+			ffd_update_enqueue(&announce->node, announce->type, announce->key, req->neigh, true);
+			ffd_neigh_unref(req->neigh);
+			free(req);
+		}
+	}
+}
+
 void ffd_announce_update(ffd_announce_t *announce) {
 	maintain_nexthops(announce);
 
@@ -125,8 +146,11 @@ 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_update_enqueue(&announce->node, announce->type, announce->key, NULL, announce->metric.metric == 0xffff);
 	}
+
+	if (announce->selected)
+		seqno_update(announce);
 }
 
 void ffd_announce_update_nexthop(ffd_announce_t *announce, ffd_nexthop_t *nexthop, ffd_metric_seqno_t ms, uint16_t interval) {
@@ -175,3 +199,84 @@ ffd_announce_t* ffd_announce_get(const ffd_node_id_t *node, uint16_t type, uint1
 
 	return announce;
 }
+
+ffd_nexthop_t* ffd_announce_nexthop_find(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;
+}
+
+ffd_nexthop_t* ffd_announce_nexthop_new(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;
+
+	ffd_neigh_ref(neigh);
+
+	return nexthop;
+}
+
+static inline bool find_seqno_request(ffd_seqno_req_t **reqp, ffd_announce_t *announce, ffd_neigh_t *neigh, uint16_t seqno) {
+	ffd_seqno_req_t *req;
+	bool ret = true;
+
+	*reqp = NULL;
+
+	for (req = announce->seqno_req_list; req; req = req->next) {
+		if (req->neigh == neigh)
+			*reqp = req;
+
+		int16_t diff = req->seqno - seqno;
+		if (timespec_diff(&now, &req->last_req) < FFD_SEQNO_REQUEST_TIMEOUT && diff >= 0)
+			ret = false;
+	}
+
+	return ret;
+}
+
+bool ffd_announce_seqno_request(ffd_announce_t *announce, ffd_neigh_t *neigh, uint16_t seqno) {
+	ffd_seqno_req_t *req;
+	bool ret = find_seqno_request(&req, announce, neigh, seqno);
+
+	if (!req) {
+		req = calloc(1, sizeof(ffd_seqno_req_t));
+		req->neigh = neigh;
+		req->seqno = seqno;
+		req->last_req = now;
+
+		ffd_neigh_ref(neigh);
+
+		req->next = announce->seqno_req_list;
+		announce->seqno_req_list = req;
+	}
+
+	int16_t diff = seqno - req->seqno;
+	if (diff > 0) {
+		req->seqno = seqno;
+		req->last_req = now;
+	}
+
+	if (ret) {
+		req->last_req = now;
+		return true;
+	}
+
+	return false;
+}
+
+void ffd_announce_free(ffd_announce_t *announce) {
+	ffd_seqno_req_t *req, *req_next;
+	for (req = announce->seqno_req_list; req; req = req_next) {
+		req_next = req->next;
+		ffd_neigh_unref(req->neigh);
+		free(req);
+	}
+
+	free(announce);
+}

ffd/ffd.c

@@ -28,6 +28,8 @@
 #include "neigh.h"
 #include "netif.h"
 #include "packet.h"
+#include "queue.h"
+#include "send.h"
 #include "tlv.h"
 #include "tlv_types.h"
 
@@ -51,10 +53,10 @@ static char *mesh = "bat0";
 int sockfd;
 struct timespec now;
 
+static ffd_queue_t *tasks = NULL;
+
 ffd_node_id_t self;
-
 ffd_iface_t *iface_list = NULL;
-
 ffd_announce_t *announce_list = NULL;
 
 
@@ -201,6 +203,15 @@ static void handle_tlv_ack_req(const ffd_tlv_ack_req_t *tlv_req, size_t len, han
 	ffd_send_ack(neigh, ntohs(tlv_req->nonce));
 }
 
+static void handle_tlv_ack(const ffd_tlv_ack_t *tlv_ack, size_t len, handle_tlv_arg_t *arg) {
+	if (len < sizeof(ffd_tlv_ack_t)) {
+		fprintf(stderr, "warn: received short acknowledement TLV.\n");
+		return;
+	}
+
+	ffd_ack_handle(ntohs(tlv_ack->nonce));
+}
+
 static void handle_tlv_hello(const ffd_tlv_hello_t *tlv_hello, size_t len, handle_tlv_arg_t *arg) {
 	if (len < sizeof(ffd_tlv_hello_t)) {
 		fprintf(stderr, "warn: received short hello TLV.\n");
@@ -284,28 +295,6 @@ 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 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;
-
-	ffd_neigh_ref(neigh);
-
-	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");
@@ -329,11 +318,11 @@ static void handle_tlv_update(const ffd_tlv_update_t *tlv_update, size_t len, ha
 	bool feasible = ffd_is_feasible(announce, ms);
 
 	ffd_neigh_t *neigh = get_tlv_neigh(arg);
-	ffd_nexthop_t *nexthop = find_nexthop(announce, neigh);
+	ffd_nexthop_t *nexthop = ffd_announce_nexthop_find(announce, neigh);
 
 	if (!nexthop) {
 		if (feasible && tlv_update->metric != 0xffff /* no need to ntohs */)
-			nexthop = new_nexthop(announce, neigh);
+			nexthop = ffd_announce_nexthop_new(announce, neigh);
 	}
 	else {
 		if (!feasible && nexthop == announce->selected) {
@@ -397,8 +386,6 @@ static void handle_tlv_seqno_req(const ffd_tlv_seqno_req_t *tlv_req, size_t len,
 		return;
 	}
 
-	fprintf(stderr, "debug: received seqno request\n");
-
 	ffd_announce_t *announce = ffd_announce_find(&tlv_req->node, ntohs(tlv_req->type), ntohs(tlv_req->key));
 
 	if (!announce) {
@@ -416,21 +403,28 @@ static void handle_tlv_seqno_req(const ffd_tlv_seqno_req_t *tlv_req, size_t len,
 	if (announce->selected->neigh == neigh)
 		return;
 
-	if ((int16_t)(ntohs(tlv_req->seqno)-announce->selected->metric_seqno.seqno) <= 0) {
+	uint16_t seqno = ntohs(tlv_req->seqno);
+
+	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_update_enqueue(&announce->node, announce->type, announce->key, neigh, true);
 		return;
 	}
 
 	if (!announce->selected->neigh) {
-		fprintf(stderr, "debug: incrementing seqno\n");
+		fprintf(stderr, "debug: received seqno request, incrementing seqno\n");
 		announce->selected->metric_seqno.seqno++;
-		ffd_send_update(NULL, neigh, announce, false);
+		ffd_update_enqueue(&announce->node, announce->type, announce->key, neigh, true);
 		return;
 	}
 
-	fprintf(stderr, "debug: received seqno request, forwarding\n");
+	if (ffd_announce_seqno_request(announce, neigh, seqno)) {
-	ffd_send_seqno_request(announce->selected->neigh, announce, ntohs(tlv_req->seqno));
+		fprintf(stderr, "debug: received seqno request, forwarding\n");
+		ffd_send_seqno_request(announce->selected->neigh, announce, seqno);
+	}
+	else {
+		fprintf(stderr, "debug: received seqno request, not forwarding again\n");
+	}
 }
 
 static void handle_tlv(ffd_tlv_type_t type, const void *data, size_t len, void *arg) {
@@ -440,7 +434,7 @@ static void handle_tlv(ffd_tlv_type_t type, const void *data, size_t len, void *
 		return;
 
 	case TLV_ACK:
-		/* we don't send ack reqs */
+		handle_tlv_ack(data, len, arg);
 		return;
 
 	case TLV_HELLO:
@@ -506,6 +500,8 @@ static void receive_packet(void) {
 }
 
 static void send_updates(void) {
+	fprintf(stderr, "debug: sending periodic updates.\n");
+
 	ffd_iface_t *iface;
 	for (iface = iface_list; iface; iface = iface->next) {
 		ffd_send_update(iface, NULL, NULL, false);
@@ -547,7 +543,7 @@ static void maintenance(void) {
 		if (!announce->nexthop_list) {
 			*cur = *next;
 			next = cur;
-			free(announce);
+			ffd_announce_free(announce);
 
 			continue;
 		}
@@ -574,6 +570,46 @@ static void maintenance(void) {
 	}
 }
 
+
+typedef struct _periodic_task_info {
+	void (*handle)(void);
+	unsigned delay;
+	unsigned interval;
+} periodic_task_info;
+
+
+static const periodic_task_info periodic_tasks [] = {
+	{maintenance, 0, FFD_MAINTENANCE_INTERVAL},
+	{ffd_send_hellos, FFD_HELLO_INTERVAL, FFD_HELLO_INTERVAL},
+	{send_updates, 1, FFD_UPDATE_INTERVAL},
+	{NULL}
+};
+
+
+static void handle_periodic_task(const struct timespec *timeout, void *arg) {
+	const periodic_task_info *info = arg;
+
+	info->handle();
+	ffd_queue_put_delayed(&tasks, handle_periodic_task, timeout, info->interval, arg);
+}
+
+static void register_periodic_tasks(void) {
+	const periodic_task_info *info;
+	for (info = periodic_tasks; info->handle; info++)
+		ffd_queue_put_delayed(&tasks, handle_periodic_task, &now, info->delay, (void*)info);
+}
+
+
+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;
@@ -585,44 +621,23 @@ int main() {
 		return 1;
 
 	update_time();
-
+	register_periodic_tasks();
-	struct timespec next_hello = now;
-	struct timespec next_update = now;
-	struct timespec next_maintenance = now;
 
 	while (true) {
-		int maintenance_timeout = timespec_diff(&next_maintenance, &now);
+		ffd_queue_run(&tasks);
-		if (maintenance_timeout <= 0) {
+		ffd_update_run();
-			maintenance();
+		ffd_ack_run();
-
-			add_interval(&next_maintenance, FFD_MAINTENANCE_INTERVAL);
-		}
-
-		int hello_timeout = timespec_diff(&next_hello, &now);
-		if (hello_timeout <= 0) {
-			ffd_send_hellos();
-
-			add_interval(&next_hello, FFD_HELLO_INTERVAL);
-		}
-
-		int update_timeout = timespec_diff(&next_update, &now);
-		if (update_timeout <= 0) {
-			fprintf(stderr, "Sending periodic update.\n");
-			send_updates();
-
-			add_interval(&next_update, FFD_UPDATE_INTERVAL);
-		}
-
-		int timeout = min(min(hello_timeout, update_timeout), maintenance_timeout);
-		if (timeout <= 0)
-			continue;
 
 		struct pollfd fds[1];
 
+		int timeout = 10*timeout_min(timeout_min(ffd_queue_timeout(&tasks), ffd_update_timeout()), ffd_ack_timeout());
+		if (timeout < 0)
+			timeout = -1;
+
 		fds[0].fd = sockfd;
 		fds[0].events = POLLIN;
 
-		poll(fds, 1, 10*timeout);
+		poll(fds, 1, timeout);
 
 		update_time();
 

ffd/ffd.h

@@ -47,8 +47,13 @@
 
 #define FFD_UPDATE_REQUEST_TIMEOUT(interval) ((interval)*13/4) /* 3.25 intervals */
 
+#define FFD_SEQNO_REQUEST_TIMEOUT 50
+
 #define FFD_MAINTENANCE_INTERVAL FFD_HELLO_INTERVAL
 
+#define FFD_DELAY (FFD_HELLO_INTERVAL/2)
+#define FFD_URGENT_DELAY 20
+#define FFD_ACK_INTERVAL FFD_URGENT_DELAY
 
 #define FFD_UPDATE_WITH_DATA 0x01
 
@@ -73,6 +78,14 @@ typedef struct _ffd_nexthop_t {
 	bool requested_update;
 } ffd_nexthop_t;
 
+typedef struct _ffd_seqno_req_t {
+	struct _ffd_seqno_req_t *next;
+
+	struct timespec last_req;
+	struct _ffd_neigh_t *neigh;
+	uint16_t seqno;
+} ffd_seqno_req_t;
+
 typedef struct _ffd_announce_t {
 	struct _ffd_announce_t *next;
 
@@ -84,6 +97,8 @@ typedef struct _ffd_announce_t {
 	uint16_t last_metric;
 	ffd_metric_seqno_t feasibility_distance;
 
+	ffd_seqno_req_t *seqno_req_list;
+
 	ffd_nexthop_t *selected;
 	ffd_nexthop_t *nexthop_list;
 
@@ -133,7 +148,6 @@ extern ffd_iface_t *iface_list;
 extern ffd_announce_t *announce_list;
 
 extern int sockfd;
-extern struct timespec now;
 
 
 #define FFD_NODE_ID_UNSPEC ((ffd_node_id_t){})
@@ -189,19 +203,18 @@ void ffd_announce_update_nexthop(ffd_announce_t *announce, ffd_nexthop_t *nextho
 ffd_announce_t* ffd_announce_new(void);
 ffd_announce_t* ffd_announce_find(const ffd_node_id_t *node, uint16_t type, uint16_t key);
 ffd_announce_t* ffd_announce_get(const ffd_node_id_t *node, uint16_t type, uint16_t key);
+ffd_nexthop_t* ffd_announce_nexthop_find(const ffd_announce_t *announce, ffd_neigh_t *neigh);
+ffd_nexthop_t* ffd_announce_nexthop_new(ffd_announce_t *announce, ffd_neigh_t *neigh);
+bool ffd_announce_seqno_request(ffd_announce_t *announce, ffd_neigh_t *neigh, uint16_t seqno);
+void ffd_announce_free(ffd_announce_t *announce);
 
-void ffd_send_ack(ffd_neigh_t *neigh, uint16_t nonce);
+void ffd_ack_handle(uint16_t n);
-void ffd_send_hellos(void);
+void ffd_ack_request(void (*cb)(uint16_t nonce, void *arg), void (*free_cb)(uint16_t nonce, void *arg), unsigned interval, unsigned retries, void *arg);
-void ffd_send_update(ffd_iface_t *iface, ffd_neigh_t *neigh, ffd_announce_t *announce, bool with_data);
+int ffd_ack_timeout(void);
-void ffd_send_retract(ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uint16_t key);
+void ffd_ack_run(void);
-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);
 
-static inline void ffd_send_seqno_request_for(ffd_neigh_t *neigh, ffd_announce_t *announce) {
+void ffd_update_enqueue(const ffd_node_id_t *node, uint16_t type, uint16_t key, ffd_neigh_t *neigh, bool urgent);
-	if (FFD_IS_INFINITY(announce->feasibility_distance))
+int ffd_update_timeout(void);
-		return;
+void ffd_update_run(void);
-
-	ffd_send_seqno_request(neigh, announce, announce->feasibility_distance.seqno+1);
-}
 
 #endif /* _FFD_FFD_H_ */

ffd/neigh.c

@@ -25,6 +25,7 @@
 
 
 #include "neigh.h"
+#include "send.h"
 
 
 ffd_neigh_t* ffd_neigh_get(ffd_iface_t *iface, const eth_addr_t *addr) {
@@ -55,6 +56,11 @@ void ffd_neigh_unref_list(ffd_neigh_t *neigh) {
 	}
 }
 
+void ffd_neigh_unref(ffd_neigh_t *neigh) {
+	if (!(--neigh->ref) && !neigh->iface)
+		free(neigh);
+}
+
 uint16_t ffd_neigh_get_rxcost(const ffd_neigh_t *neigh) {
 	if (!neigh->hello_log || !neigh->hello_interval || !neigh->iface)
 		return 0xffff;

ffd/neigh.h

@@ -44,10 +44,6 @@ static inline void ffd_neigh_ref(ffd_neigh_t *neigh) {
 	neigh->ref++;
 }
 
-static inline void ffd_neigh_unref(ffd_neigh_t *neigh) {
-	if (!(--neigh->ref) && !neigh->iface)
-		free(neigh);
-}
 
 ffd_neigh_t* ffd_neigh_get(ffd_iface_t *iface, const eth_addr_t *addr);
 void ffd_neigh_unref(ffd_neigh_t *neigh);

ffd/queue.c

@@ -0,0 +1,42 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "queue.h"
+
+
+void ffd_queue_put(ffd_queue_t **queue, ffd_queue_cb cb, const struct timespec *timeout, void *arg) {
+	while (*queue && timespec_after(timeout, &(*queue)->timeout))
+		queue = &(*queue)->next;
+
+	ffd_queue_t *entry = malloc(sizeof(ffd_queue_t));
+
+	entry->cb = cb;
+	entry->timeout = *timeout;
+	entry->arg = arg;
+
+	entry->next = *queue;
+	*queue = entry;
+}

ffd/queue.h

@@ -0,0 +1,75 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FFD_QUEUE_H_
+#define _FFD_QUEUE_H_
+
+#include "util.h"
+
+
+typedef void (*ffd_queue_cb)(const struct timespec *timeout, void *arg);
+
+struct _ffd_queue_t {
+	ffd_queue_t *next;
+	ffd_queue_cb cb;
+	struct timespec timeout;
+	void *arg;
+};
+
+
+void ffd_queue_put(ffd_queue_t **queue, ffd_queue_cb cb, const struct timespec *timeout, void *arg);
+
+
+static inline void ffd_queue_put_delayed(ffd_queue_t **queue, ffd_queue_cb cb, const struct timespec *timeout, int delay, void *arg) {
+	struct timespec timeout_delayed = *timeout;
+	add_interval(&timeout_delayed, delay);
+	ffd_queue_put(queue, cb, &timeout_delayed, arg);
+}
+
+static inline void ffd_queue_drop(ffd_queue_t **queue) {
+	ffd_queue_t *entry = *queue;
+	*queue = entry->next;
+	free(entry);
+}
+
+static inline void ffd_queue_run(ffd_queue_t **queue) {
+	while (*queue && timespec_after(&now, &(*queue)->timeout)) {
+		ffd_queue_t *entry = *queue;
+		*queue = (*queue)->next;
+
+		entry->cb(&entry->timeout, entry->arg);
+		free(entry);
+	}
+}
+
+static inline int ffd_queue_timeout(ffd_queue_t *const *queue) {
+	if (!*queue)
+		return -1;
+
+	return max(timespec_diff(&(*queue)->timeout, &now), 0);
+}
+
+#endif /* _FFD_QUEUE_H_ */

ffd/send.c

@@ -27,6 +27,7 @@
 #include "ffd.h"
 #include "neigh.h"
 #include "packet.h"
+#include "send.h"
 #include "tlv.h"
 #include "tlv_types.h"
 
@@ -40,6 +41,27 @@
 #include <sys/uio.h>
 
 
+
+typedef struct _announce_info_t {
+	ffd_node_id_t node;
+	uint16_t type;
+	uint16_t key;
+} announce_info_t;
+
+struct _ffd_update_t {
+	ffd_iface_t *iface;
+	ffd_neigh_t *neigh;
+
+	ffd_packet_t *packet;
+	size_t max_len;
+
+	ffd_node_id_t node;
+
+	unsigned n_updates;
+	announce_info_t announces[];
+};
+
+
 static bool send_eth(const eth_addr_t *addr, unsigned ifindex, const void *buf, size_t len) {
 	static const uint8_t zeros[46] = {0};
 
@@ -166,6 +188,18 @@ void ffd_send_hellos(void) {
 	}
 }
 
+static bool add_ack_request(ffd_packet_t *packet, uint16_t nonce) {
+	ffd_tlv_ack_req_t *tlv = ffd_tlv_add(packet, FFD_PACKET_MAX, TLV_ACK_REQ, sizeof(ffd_tlv_ack_req_t));
+	if (!tlv)
+		return false;
+
+	tlv->reserved = 0;
+	tlv->nonce = htons(nonce);
+	tlv->interval = htons(FFD_ACK_INTERVAL);
+
+	return true;
+}
+
 static bool add_node_id(ffd_packet_t *packet, size_t max_len, ffd_node_id_t node_id) {
 	ffd_tlv_node_id_t *tlv = ffd_tlv_add(packet, FFD_PACKET_MAX, TLV_NODE_ID, sizeof(ffd_tlv_node_id_t));
 	if (!tlv)
@@ -223,6 +257,34 @@ static bool add_update(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node
 	return true;
 }
 
+static bool add_retract(ffd_packet_t *packet, size_t max_len, ffd_node_id_t *node_id, ffd_node_id_t node, uint16_t type, uint16_t key) {
+	uint16_t len = packet->len;
+
+	if (!node_id || !ffd_are_node_ids_equal(node_id, &node)) {
+		if (!add_node_id(packet, max_len, node))
+			return false;
+
+		if (node_id)
+			*node_id = node;
+	}
+
+	ffd_tlv_update_t *update = ffd_tlv_add(packet, FFD_PACKET_MAX, TLV_UPDATE, sizeof(ffd_tlv_update_t));
+	if (!update) {
+		packet->len = len;
+		return false;
+	}
+
+	update->flags = 0;
+	update->reserved = 0;
+	update->interval = htons(FFD_UPDATE_INTERVAL);
+	update->seqno = 0;
+	update->metric = 0xffff; /* no need to htons */
+	update->type = htons(type);
+	update->key = htons(key);
+
+	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);
 
@@ -264,21 +326,83 @@ void ffd_send_retract(ffd_neigh_t *neigh, ffd_node_id_t node, uint16_t type, uin
 	if (!add_node_id(packet, FFD_PACKET_MAX, node))
 		return;
 
-	ffd_tlv_update_t *req = ffd_tlv_add(packet, FFD_PACKET_MAX, TLV_UPDATE, sizeof(ffd_tlv_update_t));
+	ffd_tlv_update_t *update = ffd_tlv_add(packet, FFD_PACKET_MAX, TLV_UPDATE, sizeof(ffd_tlv_update_t));
-	if (!req)
+	if (!update)
 		return;
 
-	req->flags = 0;
+	update->flags = 0;
-	req->reserved = 0;
+	update->reserved = 0;
-	req->interval = htons(FFD_UPDATE_INTERVAL);
+	update->interval = htons(FFD_UPDATE_INTERVAL);
-	req->seqno = 0;
+	update->seqno = 0;
-	req->metric = 0xffff; /* no need to htons */
+	update->metric = 0xffff; /* no need to htons */
-	req->type = htons(type);
+	update->type = htons(type);
-	req->key = htons(key);
+	update->key = htons(key);
 
 	send_neigh(neigh, packet);
 }
 
+ffd_update_t* ffd_send_update_new(ffd_iface_t *iface, ffd_neigh_t *neigh, const uint16_t *nonce) {
+	unsigned max_updates = (FFD_PACKET_MAX+sizeof(ffd_tlv_update_t)+1)/(sizeof(ffd_tlv_update_t)+2);
+	ffd_update_t *update = calloc(1, sizeof(ffd_update_t) + max_updates*sizeof(announce_info_t));
+	update->iface = iface;
+	update->neigh = neigh;
+
+	update->max_len = FFD_PACKET_MAX;
+	update->packet = malloc(sizeof(ffd_packet_t)+FFD_PACKET_MAX);
+	update->packet->version_magic = htons(FFD_VERSION_MAGIC);
+	update->packet->len = 0;
+
+	if (nonce)
+		add_ack_request(update->packet, *nonce);
+
+	return update;
+}
+
+static inline bool is_update_duplicate(ffd_update_t *update, ffd_node_id_t node, uint16_t type, uint16_t key) {
+	unsigned i;
+	for (i = 0; i < update->n_updates; i++) {
+		if (ffd_are_node_ids_equal(&update->announces[i].node, &node)
+		    && update->announces[i].type == type && update->announces[i].key == key)
+			return true;
+	}
+
+	return false;
+}
+
+bool ffd_send_update_add(ffd_update_t *update, ffd_announce_t *announce) {
+	if (is_update_duplicate(update, announce->node, announce->type, announce->key))
+		return false;
+
+	if (!add_update(update->packet, update->max_len, &update->node, announce, false, update->neigh))
+		return false;
+
+	update->announces[update->n_updates++] = (announce_info_t){announce->node, announce->type, announce->key};
+
+	return true;
+}
+
+bool ffd_send_update_retract(ffd_update_t *update, ffd_node_id_t node, uint16_t type, uint16_t key) {
+	if (is_update_duplicate(update, node, type, key))
+		return false;
+
+	if (!add_retract(update->packet, update->max_len, &update->node, node, type, key))
+		return false;
+
+	update->announces[update->n_updates++] = (announce_info_t){node, type, key};
+
+	return true;
+}
+
+void ffd_send_update_finish(ffd_update_t *update) {
+	fprintf(stderr, "debug: sending %u aggregated update(s).\n", update->n_updates);
+
+	if (update->packet->len)
+		send_any(update->iface, update->neigh, update->packet);
+
+	free(update->packet);
+	free(update);
+}
+
 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);
 

ffd/send.h

@@ -0,0 +1,56 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FFD_SEND_H_
+#define _FFD_SEND_H_
+
+#include "ffd.h"
+
+
+typedef struct _ffd_update_t ffd_update_t;
+
+
+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_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);
+
+ffd_update_t* ffd_send_update_new(ffd_iface_t *iface, ffd_neigh_t *neigh, const uint16_t *nonce);
+bool ffd_send_update_add(ffd_update_t *update, ffd_announce_t *announce);
+bool ffd_send_update_retract(ffd_update_t *update, ffd_node_id_t node, uint16_t type, uint16_t key);
+void ffd_send_update_finish(ffd_update_t *update);
+
+
+static inline void ffd_send_seqno_request_for(ffd_neigh_t *neigh, ffd_announce_t *announce) {
+	if (FFD_IS_INFINITY(announce->feasibility_distance))
+		return;
+
+	ffd_send_seqno_request(neigh, announce, announce->feasibility_distance.seqno+1);
+}
+
+#endif /* _FFD_SEND_H_ */

ffd/types.h

@@ -41,6 +41,6 @@ typedef struct __attribute__((packed)) _eth_addr_t {
 
 
 typedef struct _ffd_packet_t ffd_packet_t;
-
+typedef struct _ffd_queue_t ffd_queue_t;
 
 #endif /* _FFD_TYPES_H_ */

ffd/update.c

@@ -0,0 +1,158 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "ffd.h"
+#include "neigh.h"
+#include "queue.h"
+#include "send.h"
+
+#include <stdio.h>
+
+
+static ffd_queue_t *pending_updates = NULL;
+
+
+typedef struct _update_arg_t {
+	ffd_node_id_t node;
+	uint16_t type;
+	uint16_t key;
+
+	ffd_neigh_t *neigh;
+	unsigned ref;
+} update_arg_t;
+
+
+static inline update_arg_t* update_new(const ffd_node_id_t *node, uint16_t type, uint16_t key, ffd_neigh_t *neigh) {
+	update_arg_t *arg = malloc(sizeof(update_arg_t));
+
+	arg->node = *node;
+	arg->type = type;
+	arg->key = key;
+
+	if (neigh)
+		ffd_neigh_ref(neigh);
+	arg->neigh = neigh;
+
+	arg->ref = 0;
+
+	return arg;
+}
+
+static inline update_arg_t* update_ref(update_arg_t *arg) {
+	arg->ref++;
+	return arg;
+}
+
+static inline void update_unref(update_arg_t *arg) {
+	if (!--arg->ref) {
+		if (arg->neigh)
+			ffd_neigh_unref(arg->neigh);
+
+		free(arg);
+	}
+}
+
+static void update_request_ack(uint16_t nonce, void *argp) {
+	update_arg_t *arg = argp;
+
+	fprintf(stderr, "debug: sending acked update with nonce %u.\n", nonce);
+
+	ffd_update_t *update = ffd_send_update_new(NULL, arg->neigh, &nonce);
+
+	ffd_announce_t *announce = ffd_announce_find(&arg->node, arg->type, arg->key);
+
+	if (announce)
+		ffd_send_update_add(update, announce);
+	else
+		ffd_send_update_retract(update, arg->node, arg->type, arg->key);
+
+	ffd_send_update_finish(update);
+}
+
+static void update_request_ack_free(uint16_t nonce, void *arg) {
+	update_unref(arg);
+}
+
+void ffd_update_enqueue(const ffd_node_id_t *node, uint16_t type, uint16_t key, ffd_neigh_t *neigh, bool urgent) {
+	if (neigh)
+		ffd_neigh_ref(neigh);
+
+	update_arg_t *arg = update_new(node, type, key, neigh);
+
+	if (urgent) {
+		if (neigh) {
+			ffd_ack_request(update_request_ack, update_request_ack_free, FFD_ACK_INTERVAL, 10, update_ref(arg));
+		}
+		else {
+			int i;
+			for (i = 1; i <= 5; i++)
+				ffd_queue_put_delayed(&pending_updates, NULL, &now, i*FFD_URGENT_DELAY, update_ref(arg));
+		}
+	}
+	else {
+		ffd_queue_put_delayed(&pending_updates, NULL, &now, FFD_DELAY, update_ref(arg));
+	}
+}
+
+int ffd_update_timeout(void) {
+	return ffd_queue_timeout(&pending_updates);
+}
+
+void ffd_update_run(void) {
+	while (!ffd_update_timeout()) {
+		ffd_neigh_t *neigh = ((update_arg_t*)pending_updates->arg)->neigh;
+
+		ffd_update_t *update = ffd_send_update_new(NULL, neigh, NULL);
+
+		fprintf(stderr, "debug: sending scheduled updates.\n");
+
+		ffd_queue_t **entry;
+		for (entry = &pending_updates; *entry;) {
+			update_arg_t *arg = (*entry)->arg;
+
+			if (arg->neigh != neigh) {
+				entry = &(*entry)->next;
+				continue;
+			}
+
+			ffd_announce_t *announce = ffd_announce_find(&arg->node, arg->type, arg->key);
+			bool ret;
+
+			if (announce)
+				ret = ffd_send_update_add(update, announce);
+			else
+				ret = ffd_send_update_retract(update, arg->node, arg->type, arg->key);
+
+			if (!ret)
+				break;
+
+			update_unref(arg);
+			ffd_queue_drop(entry);
+		}
+
+		ffd_send_update_finish(update);
+	}
+}

ffd/util.h

@@ -34,6 +34,9 @@
 #include <time.h>
 
 
+extern struct timespec now;
+
+
 bool file_readv(const char *file, const char *format, va_list ap);
 void random_bytes(void *buffer, size_t len);
 
@@ -53,6 +56,11 @@ static inline bool are_eth_addrs_equal(const eth_addr_t *address1, const eth_add
 	return (a[0]==b[0] && a[1]==b[1] && a[2]==b[2] && a[3]==b[3] && a[4]==b[4] && a[5]==b[5]);
 }
 
+static inline bool timespec_after(const struct timespec *tp1, const struct timespec *tp2) {
+	return (tp1->tv_sec > tp2->tv_sec ||
+		(tp1->tv_sec == tp2->tv_sec && tp1->tv_nsec > tp2->tv_nsec));
+}
+
 /* returns (tp1 - tp2) in centiseconds  */
 static inline int timespec_diff(const struct timespec *tp1, const struct timespec *tp2) {
 	return ((tp1->tv_sec - tp2->tv_sec))*100 + (tp1->tv_nsec - tp2->tv_nsec)/1e7;