Limit resolve frequency

7 files changed, 41 insertions, 8 deletions

diff --git a/src/config.c b/src/config.c
index d017325..64903cb 100644
--- a/src/config.c
+++ b/src/config.c
@@ -63,6 +63,8 @@ static void default_config(fastd_config *conf) {
 	conf->reorder_count = 64;
 	conf->reorder_time = 10;
 
+	conf->min_resolve_interval = 15;
+
 	conf->ifname = NULL;
 
 	memset(&conf->bind_addr_in, 0, sizeof(struct sockaddr_in));
diff --git a/src/fastd.c b/src/fastd.c
index afa36eb..1f5c2bf 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -416,7 +416,7 @@ static void handle_tasks(fastd_context *ctx) {
 		switch (task->type) {
 		case TASK_HANDSHAKE:
 			if (fastd_peer_is_dynamic(task->peer))
-				fastd_resolve_peer(ctx, task->peer->config);
+				fastd_resolve_peer(ctx, task->peer);
 			else
 				send_handshake(ctx, task->peer);
 			break;
@@ -576,6 +576,8 @@ static void handle_resolv_returns(fastd_context *ctx) {
 		if (!fastd_peer_config_matches_dynamic(peer->config, &resolve_return.constraints))
 			continue;
 
+		peer->last_resolve_return = ctx->now;
+
 		if (fastd_peer_claim_address(ctx, peer, &resolve_return.addr)) {
 			send_handshake(ctx, peer);
 		}
diff --git a/src/fastd.h b/src/fastd.h
index c586eed..add22f2 100644
--- a/src/fastd.h
+++ b/src/fastd.h
@@ -136,6 +136,8 @@ struct _fastd_config {
 	unsigned reorder_count;
 	unsigned reorder_time;
 
+	unsigned min_resolve_interval;
+
 	char *ifname;
 
 	struct sockaddr_in bind_addr_in;
@@ -222,7 +224,7 @@ void fastd_send(fastd_context *ctx, const fastd_peer_address *address, fastd_buf
 void fastd_send_handshake(fastd_context *ctx, const fastd_peer_address *address, fastd_buffer buffer);
 void fastd_handle_receive(fastd_context *ctx, fastd_peer *peer, fastd_buffer buffer);
 
-void fastd_resolve_peer(fastd_context *ctx, const fastd_peer_config *peer);
+void fastd_resolve_peer(fastd_context *ctx, fastd_peer *peer);
 
 int fastd_vsnprintf(const fastd_context *ctx, char *buffer, size_t size, const char *format, va_list ap);
 void fastd_logf(const fastd_context *ctx, int level, const char *format, ...);
diff --git a/src/peer.c b/src/peer.c
index 23cb170..078bfdc 100644
--- a/src/peer.c
+++ b/src/peer.c
@@ -176,6 +176,8 @@ static inline void setup_peer(fastd_context *ctx, fastd_peer *peer) {
 		peer->address = peer->config->address;
 
 	peer->established = false;
+	peer->last_resolve = (struct timespec){0, 0};
+	peer->last_resolve_return = (struct timespec){0, 0};
 	peer->seen = (struct timespec){0, 0};
 	peer->protocol_state = NULL;
 
@@ -284,6 +286,7 @@ bool fastd_peer_claim_address(fastd_context *ctx, fastd_peer *new_peer, const fa
 					break;
 				}
 				else {
+					memset(&new_peer->address, 0, sizeof(fastd_peer_address));
 					return false;
 				}
 			}
diff --git a/src/peer.h b/src/peer.h
index cf16629..15a5769 100644
--- a/src/peer.h
+++ b/src/peer.h
@@ -39,6 +39,8 @@ struct _fastd_peer {
 
 	bool established;
 
+	struct timespec last_resolve;
+	struct timespec last_resolve_return;
 	struct timespec seen;
 
 	fastd_protocol_peer_state *protocol_state;
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c
index 1772f4b..75360b7 100644
--- a/src/protocol_ec25519_fhmqvc.c
+++ b/src/protocol_ec25519_fhmqvc.c
@@ -511,7 +511,7 @@ static const fastd_peer_config* match_sender_key(fastd_context *ctx, const fastd
 					return config;
 				}
 				else { /* matches dynamic */
-					fastd_resolve_peer(ctx, config);
+					fastd_resolve_peer(ctx, get_peer(ctx, config));
 					return NULL;
 				}
 			}
diff --git a/src/resolve.c b/src/resolve.c
index 2a913d8..8faffe2 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -85,7 +85,7 @@ static void* resolve_peer(void *varg) {
 	}
 
 	if (write(arg->ctx->resolvewfd, &ret, sizeof(ret)) < 0)
-		exit_errno(arg->ctx, "write");
+		pr_error_errno(arg->ctx, "can't write resolve return");
 
 	freeaddrinfo(res);
 	free(arg);
@@ -93,15 +93,37 @@ static void* resolve_peer(void *varg) {
 	return NULL;
 }
 
-void fastd_resolve_peer(fastd_context *ctx, const fastd_peer_config *peer) {
-	pr_verbose(ctx, "resolving host `%s' for peer `%s'...", peer->hostname, peer->name);
+void fastd_resolve_peer(fastd_context *ctx, fastd_peer *peer) {
+	if (timespec_after(&peer->last_resolve, &peer->last_resolve_return)) {
+		pr_debug(ctx, "not resolving %P as there is already a resolve running", peer);
+		return;
+	}
+
+	if (timespec_diff(&ctx->now, &peer->last_resolve) < ctx->conf->min_resolve_interval*1000) {
+		pr_debug(ctx, "not resolving %P as it has been resolved a short time ago", peer);
+
+		fastd_resolve_return ret;
+		memset(&ret, 0, sizeof(ret));
+
+		ret.hostname = strdup(peer->config->hostname);
+		ret.constraints = peer->config->address;
+		ret.addr = peer->address;
+
+		if (write(ctx->resolvewfd, &ret, sizeof(ret)) < 0)
+			pr_error_errno(ctx, "can't write resolve return");
+
+		return;
+	}
+
+	pr_verbose(ctx, "resolving host `%s' for peer %P...", peer->config->hostname, peer);
+	peer->last_resolve = ctx->now;
 
 	resolv_arg *arg = malloc(sizeof(resolv_arg));
 
 	arg->ctx = ctx;
 	arg->master_thread = pthread_self();
-	arg->hostname = strdup(peer->hostname);
-	arg->constraints = peer->address;
+	arg->hostname = strdup(peer->config->hostname);
+	arg->constraints = peer->config->address;
 
 	pthread_t thread;
 	if (pthread_create(&thread, NULL, resolve_peer, arg) != 0) {