From 261bf354b7644a99ace081a6ad6c7b8db8a1f51e Mon Sep 17 00:00:00 2001
From: Wouter Wijngaards <wouter@nlnetlabs.nl>
Date: Wed, 23 May 2018 13:55:09 +0000
Subject: [PATCH] - Use accept4 to speed up incoming TCP (and TLS) connections,
   available on Linux and FreeBSD.

git-svn-id: file:///svn/unbound/trunk@4686 be551aaa-1e26-0410-a405-d3ace91eadb9
---
 config.h.in     | 3 +++
 configure       | 2 +-
 configure.ac    | 2 +-
 doc/Changelog   | 4 ++++
 util/netevent.c | 7 +++++++
 5 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/config.h.in b/config.h.in
index 922389428..04356f334 100644
--- a/config.h.in
+++ b/config.h.in
@@ -30,6 +30,9 @@
    internal symbols */
 #undef EXPORT_ALL_SYMBOLS
 
+/* Define to 1 if you have the `accept4' function. */
+#undef HAVE_ACCEPT4
+
 /* Define to 1 if you have the `arc4random' function. */
 #undef HAVE_ARC4RANDOM
 
diff --git a/configure b/configure
index fcb49c2de..45cb7198d 100755
--- a/configure
+++ b/configure
@@ -19702,7 +19702,7 @@ if test "$ac_res" != no; then :
 
 fi
 
-for ac_func in tzset sigprocmask fcntl getpwnam endpwent getrlimit setrlimit setsid chroot kill chown sleep usleep random srandom recvmsg sendmsg writev socketpair glob initgroups strftime localtime_r setusercontext _beginthreadex endservent endprotoent fsync shmget
+for ac_func in tzset sigprocmask fcntl getpwnam endpwent getrlimit setrlimit setsid chroot kill chown sleep usleep random srandom recvmsg sendmsg writev socketpair glob initgroups strftime localtime_r setusercontext _beginthreadex endservent endprotoent fsync shmget accept4
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.ac b/configure.ac
index 11f2ff56c..35a1096eb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1319,7 +1319,7 @@ AC_INCLUDES_DEFAULT
 #endif
 ])
 AC_SEARCH_LIBS([setusercontext], [util])
-AC_CHECK_FUNCS([tzset sigprocmask fcntl getpwnam endpwent getrlimit setrlimit setsid chroot kill chown sleep usleep random srandom recvmsg sendmsg writev socketpair glob initgroups strftime localtime_r setusercontext _beginthreadex endservent endprotoent fsync shmget])
+AC_CHECK_FUNCS([tzset sigprocmask fcntl getpwnam endpwent getrlimit setrlimit setsid chroot kill chown sleep usleep random srandom recvmsg sendmsg writev socketpair glob initgroups strftime localtime_r setusercontext _beginthreadex endservent endprotoent fsync shmget accept4])
 AC_CHECK_FUNCS([setresuid],,[AC_CHECK_FUNCS([setreuid])])
 AC_CHECK_FUNCS([setresgid],,[AC_CHECK_FUNCS([setregid])])
 
diff --git a/doc/Changelog b/doc/Changelog
index 5decbe67b..f00148911 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,7 @@
+23 May 2018: Wouter
+	- Use accept4 to speed up incoming TCP (and TLS) connections,
+	  available on Linux and FreeBSD.
+
 17 May 2018: Ralph
 	- Qname minimisation default changed to yes.
 
diff --git a/util/netevent.c b/util/netevent.c
index 34a1bd5e1..3c3537856 100644
--- a/util/netevent.c
+++ b/util/netevent.c
@@ -764,7 +764,12 @@ int comm_point_perform_accept(struct comm_point* c,
 {
 	int new_fd;
 	*addrlen = (socklen_t)sizeof(*addr);
+#ifndef HAVE_ACCEPT4
 	new_fd = accept(c->fd, (struct sockaddr*)addr, addrlen);
+#else
+	/* SOCK_NONBLOCK saves extra calls to fcntl for the same result */
+	new_fd = accept4(c->fd, (struct sockaddr*)addr, addrlen, SOCK_NONBLOCK);
+#endif
 	if(new_fd == -1) {
 #ifndef USE_WINSOCK
 		/* EINTR is signal interrupt. others are closed connection. */
@@ -827,7 +832,9 @@ int comm_point_perform_accept(struct comm_point* c,
 #endif
 		return -1;
 	}
+#ifndef HAVE_ACCEPT4
 	fd_set_nonblock(new_fd);
+#endif
 	return new_fd;
 }