Simplify keepalive sending

By using a global keepalive timer, the O(n) keepalive queue purge operation on
every send operation is avoided.

7 files changed, 54 insertions, 102 deletions

diff --git a/src/config.c b/src/config.c
index 48a9c8c..1be93b0 100644
--- a/src/config.c
+++ b/src/config.c
@@ -89,7 +89,8 @@ static void default_config(fastd_config_t *conf) {
 
 	conf->log_syslog_ident = strdup("fastd");
 
-	conf->keepalive_interval = 20;
+	conf->keepalive_interval = 10;
+	conf->keepalive_timeout = 15;
 	conf->peer_stale_time = 90;
 	conf->eth_addr_stale_time = 300;
 
diff --git a/src/fastd.c b/src/fastd.c
index 173e5f3..786f158 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -425,37 +425,27 @@ static void send_handshake(fastd_context_t *ctx, fastd_peer_t *peer) {
 static void handle_tasks(fastd_context_t *ctx) {
 	fastd_task_t *task;
 	while ((task = fastd_task_get(ctx)) != NULL) {
-		switch (task->type) {
-		case TASK_HANDSHAKE:
-			fastd_peer_schedule_handshake(ctx, task->peer);
+		fastd_peer_schedule_handshake(ctx, task->peer);
 
-			if(!fastd_peer_may_connect(ctx, task->peer)) {
-				task->peer->next_remote = task->peer->remotes;
-				break;
-			}
-
-			send_handshake(ctx, task->peer);
-
-			if (fastd_peer_is_established(task->peer))
-				break;
-
-			task->peer->next_remote = task->peer->next_remote->next;
-			if (!task->peer->next_remote)
-				task->peer->next_remote = task->peer->remotes;
+		if(!fastd_peer_may_connect(ctx, task->peer)) {
+			task->peer->next_remote = task->peer->remotes;
+			free(task);
+			continue;
+		}
 
-			if (fastd_remote_is_dynamic(task->peer->next_remote))
-				fastd_resolve_peer(ctx, task->peer, task->peer->next_remote);
+		send_handshake(ctx, task->peer);
 
-			break;
+		if (fastd_peer_is_established(task->peer)) {
+			free(task);
+			continue;
+		}
 
-		case TASK_KEEPALIVE:
-			pr_debug2(ctx, "sending keepalive to %P", task->peer);
-			ctx->conf->protocol->send(ctx, task->peer, fastd_buffer_alloc(ctx, 0, ctx->conf->min_encrypt_head_space, ctx->conf->min_encrypt_tail_space));
-			break;
+		task->peer->next_remote = task->peer->next_remote->next;
+		if (!task->peer->next_remote)
+			task->peer->next_remote = task->peer->remotes;
 
-		default:
-			exit_bug(ctx, "invalid task type");
-		}
+		if (fastd_remote_is_dynamic(task->peer->next_remote))
+			fastd_resolve_peer(ctx, task->peer, task->peer->next_remote);
 
 		free(task);
 	}
@@ -557,10 +547,14 @@ static void handle_input(fastd_context_t *ctx) {
 	if (i != n_fds)
 		exit_bug(ctx, "fd count mismatch");
 
-	int timeout = fastd_task_timeout(ctx);
+	int keepalive_timeout = timespec_diff(&ctx->next_keepalives, &ctx->now);
 
-	if (timeout < 0 || timeout > 60000)
-		timeout = 60000; /* call maintenance at least once a minute */
+	if (keepalive_timeout < 0)
+		keepalive_timeout = 0;
+
+	int timeout = fastd_task_timeout(ctx);
+	if (timeout < 0 || timeout > keepalive_timeout)
+		timeout = keepalive_timeout;
 
 	int ret = poll(fds, n_fds, timeout);
 	if (ret < 0) {
@@ -628,6 +622,22 @@ static void maintenance(fastd_context_t *ctx) {
 	fastd_peer_eth_addr_cleanup(ctx);
 
 	fastd_socket_handle_binds(ctx);
+
+	if (timespec_after(&ctx->now, &ctx->next_keepalives)) {
+		fastd_peer_t *peer;
+		for (peer = ctx->peers; peer; peer = peer->next) {
+			if (!fastd_peer_is_established(peer))
+				continue;
+
+			if (timespec_diff(&ctx->now, &peer->last_send) < (int)ctx->conf->keepalive_timeout*1000)
+				continue;
+
+			pr_debug2(ctx, "sending keepalive to %P", peer);
+			ctx->conf->protocol->send(ctx, peer, fastd_buffer_alloc(ctx, 0, ctx->conf->min_encrypt_head_space, ctx->conf->min_encrypt_tail_space));
+		}
+
+		ctx->next_keepalives.tv_sec += ctx->conf->keepalive_interval;
+	}
 }
 
 
@@ -748,6 +758,9 @@ int main(int argc, char *argv[]) {
 
 	update_time(&ctx);
 
+	ctx.next_keepalives = ctx.now;
+	ctx.next_keepalives.tv_sec += conf.keepalive_interval;
+
 	pr_info(&ctx, "fastd " FASTD_VERSION " starting");
 
 	fastd_cap_init(&ctx);
diff --git a/src/fastd.h b/src/fastd.h
index c6e25cb..133e2e0 100644
--- a/src/fastd.h
+++ b/src/fastd.h
@@ -167,6 +167,7 @@ struct fastd_config {
 	char *log_syslog_ident;
 	fastd_log_file_t *log_files;
 
+	unsigned keepalive_timeout;
 	unsigned keepalive_interval;
 	unsigned peer_stale_time;
 	unsigned eth_addr_stale_time;
@@ -277,6 +278,7 @@ struct fastd_context {
 	fastd_peer_t *peers;
 	fastd_peer_t *peers_temp;
 	fastd_queue_t task_queue;
+	struct timespec next_keepalives;
 
 	int resolverfd;
 	int resolvewfd;
diff --git a/src/peer.h b/src/peer.h
index 5a73abd..39b17a8 100644
--- a/src/peer.h
+++ b/src/peer.h
@@ -43,6 +43,7 @@ struct fastd_peer {
 
 	fastd_peer_state_t state;
 	struct timespec seen;
+	struct timespec last_send;
 
 	fastd_remote_t *remotes;
 	fastd_remote_t *next_remote;
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c
index fd9c6a4..d1d4740 100644
--- a/src/protocol_ec25519_fhmqvc.c
+++ b/src/protocol_ec25519_fhmqvc.c
@@ -435,8 +435,6 @@ static bool establish(fastd_context_t *ctx, fastd_peer_t *peer, const fastd_meth
 
 	pr_verbose(ctx, "new session with %P established using method `%s'.", peer, method->name);
 
-	fastd_task_schedule_keepalive(ctx, peer, ctx->conf->keepalive_interval*1000);
-
 	if (initiator)
 		fastd_peer_schedule_handshake(ctx, peer);
 	else
@@ -795,7 +793,7 @@ static void protocol_handle_recv(fastd_context_t *ctx, fastd_peer_t *peer, fastd
 
 			if (!peer->protocol_state->session.handshakes_cleaned) {
 				pr_debug(ctx, "cleaning left handshakes with %P", peer);
-				fastd_task_delete_peer_handshakes(ctx, peer);
+				fastd_task_delete_peer(ctx, peer);
 				peer->protocol_state->session.handshakes_cleaned = true;
 
 				if (peer->protocol_state->session.method->session_is_initiator(ctx, peer->protocol_state->session.method_state))
@@ -832,9 +830,7 @@ static void session_send(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_
 	}
 
 	fastd_send(ctx, peer->sock, &peer->local_address, &peer->address, send_buffer);
-
-	fastd_task_delete_peer_keepalives(ctx, peer);
-	fastd_task_schedule_keepalive(ctx, peer, ctx->conf->keepalive_interval*1000);
+	peer->last_send = ctx->now;
 }
 
 static void protocol_send(fastd_context_t *ctx, fastd_peer_t *peer, fastd_buffer_t buffer) {
diff --git a/src/task.c b/src/task.c
index 9ed17f7..768c9c3 100644
--- a/src/task.c
+++ b/src/task.c
@@ -31,72 +31,31 @@ fastd_task_t* fastd_task_get(fastd_context_t *ctx) {
 	return container_of(fastd_queue_get(ctx, &ctx->task_queue), fastd_task_t, entry);
 }
 
-static bool is_handshake(fastd_queue_entry_t *data, void *extra) {
+static bool is_peer(fastd_queue_entry_t *data, void *extra) {
 	fastd_task_t *task = container_of(data, fastd_task_t, entry);
 	fastd_peer_t *peer = extra;
 
-	if (task->peer != peer)
-		return false;
-
-	return (task->type == TASK_HANDSHAKE);
+	return (task->peer == peer);
 }
 
 void fastd_task_schedule_handshake(fastd_context_t *ctx, fastd_peer_t *peer, int timeout) {
-	if (fastd_queue_has_entry(ctx, &ctx->task_queue, is_handshake, peer)) {
+	if (fastd_queue_has_entry(ctx, &ctx->task_queue, is_peer, peer)) {
 		pr_debug(ctx, "not sending a handshake to %P, there still is one queued", peer);
 		return;
 	}
 
 	fastd_task_t *task = malloc(sizeof(fastd_task_t));
 
-	task->type = TASK_HANDSHAKE;
 	task->peer = peer;
 
 	fastd_queue_put(ctx, &ctx->task_queue, &task->entry, timeout);
 }
 
-static bool is_keepalive(fastd_queue_entry_t *data, void *extra) {
+static bool delete_peer_task(fastd_queue_entry_t *data, void *extra) {
 	fastd_task_t *task = container_of(data, fastd_task_t, entry);
 	fastd_peer_t *peer = extra;
 
 	if (task->peer != peer)
-		return false;
-
-	return (task->type == TASK_KEEPALIVE);
-}
-
-void fastd_task_schedule_keepalive(fastd_context_t *ctx, fastd_peer_t *peer, int timeout) {
-	if (fastd_queue_has_entry(ctx, &ctx->task_queue, is_keepalive, peer)) {
-		pr_debug(ctx, "not sending a keepalive to %P, there still is one queued", peer);
-		return;
-	}
-
-	fastd_task_t *task = malloc(sizeof(fastd_task_t));
-
-	task->type = TASK_KEEPALIVE;
-	task->peer = peer;
-
-	fastd_queue_put(ctx, &ctx->task_queue, &task->entry, timeout);
-}
-
-typedef struct delete_task_extra {
-	fastd_peer_t *peer;
-	bool handshake_only;
-	bool keepalive_only;
-} delete_task_extra_t;
-
-static bool delete_task(fastd_queue_entry_t *data, void *extra) {
-	delete_task_extra_t *e = extra;
-	fastd_task_t *task = container_of(data, fastd_task_t, entry);
-	fastd_peer_t *peer = e->peer;
-
-	if (task->peer != peer)
-		return true;
-
-	if (e->handshake_only && task->type != TASK_HANDSHAKE)
-		return true;
-
-	if (e->keepalive_only && task->type != TASK_KEEPALIVE)
 		return true;
 
 	free(task);
@@ -105,16 +64,5 @@ static bool delete_task(fastd_queue_entry_t *data, void *extra) {
 }
 
 void fastd_task_delete_peer(fastd_context_t *ctx, fastd_peer_t *peer) {
-	delete_task_extra_t extra = {peer, false, false};
-	fastd_queue_filter(ctx, &ctx->task_queue, delete_task, &extra);
-}
-
-void fastd_task_delete_peer_handshakes(fastd_context_t *ctx, fastd_peer_t *peer) {
-	delete_task_extra_t extra = {peer, true, false};
-	fastd_queue_filter(ctx, &ctx->task_queue, delete_task, &extra);
-}
-
-void fastd_task_delete_peer_keepalives(fastd_context_t *ctx, fastd_peer_t *peer) {
-	delete_task_extra_t extra = {peer, false, true};
-	fastd_queue_filter(ctx, &ctx->task_queue, delete_task, &extra);
+	fastd_queue_filter(ctx, &ctx->task_queue, delete_peer_task, peer);
 }
diff --git a/src/task.h b/src/task.h
index d80ddd6..ae6b1f3 100644
--- a/src/task.h
+++ b/src/task.h
@@ -33,15 +33,9 @@
 #include <sys/uio.h>
 
 
-typedef enum fastd_task_type {
-	TASK_HANDSHAKE,
-	TASK_KEEPALIVE,
-} fastd_task_type_t;
-
 typedef struct fastd_task {
 	fastd_queue_entry_t entry;
 
-	fastd_task_type_t type;
 	fastd_peer_t *peer;
 } fastd_task_t;
 
@@ -54,10 +48,7 @@ static inline int fastd_task_timeout(fastd_context_t *ctx) {
 fastd_task_t* fastd_task_get(fastd_context_t *ctx);
 
 void fastd_task_schedule_handshake(fastd_context_t *ctx, fastd_peer_t *peer, int timeout);
-void fastd_task_schedule_keepalive(fastd_context_t *ctx, fastd_peer_t *peer, int timeout);
 
 void fastd_task_delete_peer(fastd_context_t *ctx, fastd_peer_t *peer);
-void fastd_task_delete_peer_handshakes(fastd_context_t *ctx, fastd_peer_t *peer);
-void fastd_task_delete_peer_keepalives(fastd_context_t *ctx, fastd_peer_t *peer);
 
 #endif /* _FASTD_TASK_H_ */