From: George Thessalonikefs <george@nlnetlabs.nl>
Date: Sat, 24 Jul 2021 14:16:19 +0000 (+0200)
Subject: - stream reuse, do not explicitly wait for a free pending_tcp if a reuse
X-Git-Tag: release-1.13.2rc1~19^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=de73af2da2105f2ba4cb88b0a775c59faf4bee25;p=thirdparty%2Funbound.git

- stream reuse, do not explicitly wait for a free pending_tcp if a reuse
  could be used.
---

diff --git a/services/outside_network.c b/services/outside_network.c
index 5207a7042..37f97d3dd 100644
--- a/services/outside_network.c
+++ b/services/outside_network.c
@@ -801,13 +801,59 @@ waiting_tcp_callback(struct waiting_tcp* w, struct comm_point* c, int error,
 	}
 }
 
+/** add waiting_tcp element to the outnet tcp waiting list */
+static void
+outnet_add_tcp_waiting(struct outside_network* outnet, struct waiting_tcp* w)
+{
+	struct timeval tv;
+	log_assert(!w->on_tcp_waiting_list);
+	if(w->on_tcp_waiting_list)
+		return;
+	w->next_waiting = NULL;
+	if(outnet->tcp_wait_last)
+		outnet->tcp_wait_last->next_waiting = w;
+	else	outnet->tcp_wait_first = w;
+	outnet->tcp_wait_last = w;
+	w->on_tcp_waiting_list = 1;
+#ifndef S_SPLINT_S
+	tv.tv_sec = w->timeout/1000;
+	tv.tv_usec = (w->timeout%1000)*1000;
+#endif
+	comm_timer_set(w->timer, &tv);
+}
+
+/** add waiting_tcp element as first to the outnet tcp waiting list */
+static void
+outnet_add_tcp_waiting_first(struct outside_network* outnet,
+	struct waiting_tcp* w, int reset_timer)
+{
+	struct timeval tv;
+	log_assert(!w->on_tcp_waiting_list);
+	if(w->on_tcp_waiting_list)
+		return;
+	w->next_waiting = outnet->tcp_wait_first;
+	if(!outnet->tcp_wait_last)
+		outnet->tcp_wait_last = w;
+	outnet->tcp_wait_first = w;
+	w->on_tcp_waiting_list = 1;
+	if(reset_timer) {
+#ifndef S_SPLINT_S
+		tv.tv_sec = w->timeout/1000;
+		tv.tv_usec = (w->timeout%1000)*1000;
+#endif
+		comm_timer_set(w->timer, &tv);
+	}
+	log_assert(
+		(!outnet->tcp_reuse_first && !outnet->tcp_reuse_last) ||
+		(outnet->tcp_reuse_first && outnet->tcp_reuse_last));
+}
+
 /** see if buffers can be used to service TCP queries */
 static void
 use_free_buffer(struct outside_network* outnet)
 {
 	struct waiting_tcp* w;
-	while(outnet->tcp_free && outnet->tcp_wait_first 
-		&& !outnet->want_to_quit) {
+	while(outnet->tcp_wait_first && !outnet->want_to_quit) {
 #ifdef USE_DNSTAP
 		struct pending_tcp* pend_tcp = NULL;
 #endif
@@ -848,7 +894,7 @@ use_free_buffer(struct outside_network* outnet)
 					reuse->pending->c->fd, reuse->pending,
 					w);
 			}
-		} else {
+		} else if(outnet->tcp_free) {
 			struct pending_tcp* pend = w->outnet->tcp_free;
 			rbtree_init(&pend->reuse.tree_by_id, reuse_id_cmp);
 			pend->reuse.pending = pend;
@@ -865,11 +911,15 @@ use_free_buffer(struct outside_network* outnet)
 #ifdef USE_DNSTAP
 			pend_tcp = pend;
 #endif
+		} else {
+			/* no reuse and no free buffer, put back at the start */
+			outnet_add_tcp_waiting_first(outnet, w, 0);
+			break;
 		}
 #ifdef USE_DNSTAP
 		if(outnet->dtenv && pend_tcp && w && w->sq &&
-		   (outnet->dtenv->log_resolver_query_messages ||
-		    outnet->dtenv->log_forwarder_query_messages)) {
+			(outnet->dtenv->log_resolver_query_messages ||
+			outnet->dtenv->log_forwarder_query_messages)) {
 			sldns_buffer tmp;
 			sldns_buffer_init_frm_data(&tmp, w->pkt, w->pkt_len);
 			dt_msg_send_outside_query(outnet->dtenv, &w->sq->addr,
@@ -880,27 +930,6 @@ use_free_buffer(struct outside_network* outnet)
 	}
 }
 
-/** add waiting_tcp element to the outnet tcp waiting list */
-static void
-outnet_add_tcp_waiting(struct outside_network* outnet, struct waiting_tcp* w)
-{
-	struct timeval tv;
-	log_assert(!w->on_tcp_waiting_list);
-	if(w->on_tcp_waiting_list)
-		return;
-	w->next_waiting = NULL;
-	if(outnet->tcp_wait_last)
-		outnet->tcp_wait_last->next_waiting = w;
-	else	outnet->tcp_wait_first = w;
-	outnet->tcp_wait_last = w;
-	w->on_tcp_waiting_list = 1;
-#ifndef S_SPLINT_S
-	tv.tv_sec = w->timeout/1000;
-	tv.tv_usec = (w->timeout%1000)*1000;
-#endif
-	comm_timer_set(w->timer, &tv);
-}
-
 /** delete element from tree by id */
 static void
 reuse_tree_by_id_delete(struct reuse_tcp* reuse, struct waiting_tcp* w)
diff --git a/testcode/unittcpreuse.c b/testcode/unittcpreuse.c
index ddb865b68..b93e7def1 100644
--- a/testcode/unittcpreuse.c
+++ b/testcode/unittcpreuse.c
@@ -128,7 +128,7 @@ static int create_pending_tcp(struct outside_network* outnet)
 			outnet->num_tcp, sizeof(struct pending_tcp*))))
 		return 0;
 	for(i=0; i<outnet->num_tcp; i++) {
-		if(!(outnet->tcp_conns[i] = (struct pending_tcp*)calloc(1, 
+		if(!(outnet->tcp_conns[i] = (struct pending_tcp*)calloc(1,
 			sizeof(struct pending_tcp))))
 			return 0;
 		outnet->tcp_conns[i]->next_free = outnet->tcp_free;
@@ -216,7 +216,6 @@ static void tcp_reuse_tree_list_test(void)
 	check_removal(&outnet, 2, 5);
 	check_removal(&outnet, 1, 3);
 	check_removal(&outnet, 1, 2);
-	
 	/* check snip */
 	unit_show_func("services/outside_network.c", "reuse_tcp_lru_snip");
 	check_snip(&outnet, 4);