- Fix for #882: small changes, date updated in Copyright for

util/timeval_func.c and util/timeval_func.h. Man page entries and
  example entry.

doc/Changelog

@@ -1,3 +1,12 @@
+26 April 2023: Wouter
+	- Merge #882 from vvfedorenko: Features/dropqueuedpackets, with
+	  sock-queue-timeout option that drops packets that have been in the
+	  socket queue for too long. Added statistics num.queries_timed_out
+	  and query.queue_time_us.max that track the socket queue timeouts.
+	- Fix for #882: small changes, date updated in Copyright for
+	  util/timeval_func.c and util/timeval_func.h. Man page entries and
+	  example entry.
+
 19 April 2023: Wouter
 	- Fix for #878: Invalid IP address in unbound.conf causes Segmentation
 	  Fault on OpenBSD.

doc/example.conf.in

@@ -274,6 +274,10 @@ server:
 	# Timeout for EDNS TCP keepalive, in msec.
 	# edns-tcp-keepalive-timeout: 120000
 
+	# UDP queries that have waited in the socket buffer for a long time
+	# can be dropped. Default is 0, disabled. In seconds, such as 3.
+	# sock-queue-timeout: 0
+
 	# Use systemd socket activation for UDP, TCP, and control sockets.
 	# use-systemd: no
 

doc/unbound-control.8.in

@@ -398,6 +398,14 @@ as a cache response was sent.
 .I threadX.num.expired
 number of replies that served an expired cache entry.
 .TP
+.I threadX.num.queries_timed_out
+number of queries that are dropped because they waited in the UDP socket buffer
+for too long.
+.TP
+.I threadX.query.queue_time_us.max
+The maximum wait time for packets in the socket buffer, in microseconds. This
+is only reported when sock-queue-timeout is enabled.
+.TP
 .I threadX.num.recursivereplies
 The number of replies sent to queries that needed recursive processing. Could be smaller than threadX.num.cachemiss if due to timeouts no replies were sent for some queries.
 .TP
@@ -462,6 +470,12 @@ summed over threads.
 .I total.num.expired
 summed over threads.
 .TP
+.I total.num.queries_timed_out
+summed over threads.
+.TP
+.I total.query.queue_time_us.max
+the maximum of the thread values.
+.TP
 .I total.num.recursivereplies
 summed over threads.
 .TP

doc/unbound.conf.5.in

@@ -505,6 +505,14 @@ configured, and finally to 0 if the number of free buffers falls below
 A minimum actual timeout of 200 milliseconds is observed regardless of the
 advertised timeout.
 .TP
+.B sock\-queue\-timeout: \fI<sec>\fR
+UDP queries that have waited in the socket buffer for a long time can be
+dropped. Default is 0, disabled. The time is set in seconds, 3 could be a
+good value to ignore old queries that likely the client does not need a reply
+for any more. This could happen if the host has not been able to service
+the queries for a while, i.e. Unbound is not running, and then is enabled
+again. It uses timestamp socket options.
+.TP
 .B tcp\-upstream: \fI<yes or no>
 Enable or disable whether the upstream queries use TCP only for transport.
 Default is no.  Useful in tunneling scenarios. If set to no you can specify

util/timeval_func.c

@@ -1,7 +1,7 @@
 /*
  * util/timeval_func.c - helpers to work with struct timeval values.
  *
- * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ * Copyright (c) 2023, NLnet Labs. All rights reserved.
  *
  * This software is open source.
  *
@@ -39,6 +39,7 @@
  * This file contains helpers to manipulate struct timeval values.
  */
 
+#include "config.h"
 #include "timeval_func.h"
 
 /** subtract timers and the values do not overflow or become negative */

util/timeval_func.h

@@ -1,7 +1,7 @@
 /*
- * util/timeval)func.h - definitions of helpers for strcut timeval values.
+ * util/timeval_func.h - definitions of helpers for struct timeval values.
  *
- * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ * Copyright (c) 2023, NLnet Labs. All rights reserved.
  *
  * This software is open source.
  *