diff --git a/ChangeLog b/ChangeLog
index 1e07c1bd3..b799c1c22 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,8 @@
 20110929
  - (djm) [configure.ac defines.h] No need to detect sizeof(char); patch
    from des AT des.no
+ - (dtucker) [configure.ac openbsd-compat/Makefile.in
+   openbsd-compat/strnlen.c] Add strnlen to the compat library.
 
 20110923
  - (djm) [openbsd-compat/getcwd.c] Remove OpenBSD rcsid marker since we no
diff --git a/configure.ac b/configure.ac
index 38e260ce7..95a2a8d1d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.481 2011/09/29 01:11:55 djm Exp $
+# $Id: configure.ac,v 1.482 2011/09/29 13:17:21 dtucker Exp $
 #
 # Copyright (c) 1999-2004 Damien Miller
 #
@@ -15,7 +15,7 @@
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 AC_INIT([OpenSSH], [Portable], [openssh-unix-dev@mindrot.org])
-AC_REVISION($Revision: 1.481 $)
+AC_REVISION($Revision: 1.482 $)
 AC_CONFIG_SRCDIR([ssh.c])
 AC_LANG([C])
 
@@ -1501,6 +1501,7 @@ AC_CHECK_FUNCS([ \
 	strlcat \
 	strlcpy \
 	strmode \
+	strnlen \
 	strnvis \
 	strptime \
 	strtonum \
@@ -2505,6 +2506,51 @@ elif test "x$sandbox_arg" = "xrlimit" || \
 		AC_MSG_ERROR([rlimit sandbox requires setrlimit function])
 	SANDBOX_STYLE="rlimit"
 	AC_DEFINE([SANDBOX_RLIMIT], [1], [Sandbox using setrlimit(2)])
+
+	AC_MSG_CHECKING([if select works with zero available fds])
+	AC_RUN_IFELSE(
+		[AC_LANG_PROGRAM([[
+#include <sys/time.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#include <sys/resource.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+		]], [[
+	struct rlimit rl_zero;
+	int fd, r;
+	fd_set fds;
+
+	fd = open("/dev/null", O_RDWR);
+	rl_zero.rlim_cur = rl_zero.rlim_max = 0;
+	setrlimit(RLIMIT_FSIZE, &rl_zero);
+	setrlimit(RLIMIT_NOFILE, &rl_zero);
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+	r = select(fd+1, &fds, NULL, NULL, NULL);
+	if (r == -1)
+		exit(1);
+	exit(0);
+		]])], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE([SELECT_REQUIRED_FDS], [0],
+			    [number of available fds required for select])
+		], [
+			AC_MSG_RESULT(no)
+			AC_DEFINE([SELECT_REQUIRED_FDS], [1],
+			    [number of available fds required for select])
+		], [
+			AC_MSG_RESULT([cross-compiling, assuming yes])
+			AC_DEFINE([SELECT_REQUIRED_FDS], [0],
+			    [assuming select works with zero free fds])
+		]
+	)
 elif test -z "$sandbox_arg" || test "x$sandbox_arg" = "xno" || \
      test "x$sandbox_arg" = "xnone" || test "x$sandbox_arg" = "xnull" ; then
 	SANDBOX_STYLE="none"
diff --git a/openbsd-compat/Makefile.in b/openbsd-compat/Makefile.in
index 41b22d837..fcc70fca5 100644
--- a/openbsd-compat/Makefile.in
+++ b/openbsd-compat/Makefile.in
@@ -1,4 +1,4 @@
-# $Id: Makefile.in,v 1.46 2010/10/07 11:19:24 djm Exp $
+# $Id: Makefile.in,v 1.47 2011/09/29 13:17:22 dtucker Exp $
 
 sysconfdir=@sysconfdir@
 piddir=@piddir@
@@ -16,7 +16,7 @@ RANLIB=@RANLIB@
 INSTALL=@INSTALL@
 LDFLAGS=-L. @LDFLAGS@
 
-OPENBSD=base64.o basename.o bindresvport.o daemon.o dirname.o fmt_scaled.o getcwd.o getgrouplist.o getopt.o getrrsetbyname.o glob.o inet_aton.o inet_ntoa.o inet_ntop.o mktemp.o pwcache.o readpassphrase.o realpath.o rresvport.o setenv.o setproctitle.o sha2.o sigact.o strlcat.o strlcpy.o strmode.o strptime.o strsep.o strtonum.o strtoll.o strtoul.o timingsafe_bcmp.o vis.o
+OPENBSD=base64.o basename.o bindresvport.o daemon.o dirname.o fmt_scaled.o getcwd.o getgrouplist.o getopt.o getrrsetbyname.o glob.o inet_aton.o inet_ntoa.o inet_ntop.o mktemp.o pwcache.o readpassphrase.o realpath.o rresvport.o setenv.o setproctitle.o sha2.o sigact.o strlcat.o strlcpy.o strmode.o strnlen.o strptime.o strsep.o strtonum.o strtoll.o strtoul.o timingsafe_bcmp.o vis.o
 
 COMPAT=bsd-arc4random.o bsd-asprintf.o bsd-closefrom.o bsd-cray.o bsd-cygwin_util.o bsd-getpeereid.o bsd-misc.o bsd-nextstep.o bsd-openpty.o bsd-poll.o bsd-snprintf.o bsd-statvfs.o bsd-waitpid.o fake-rfc2553.o openssl-compat.o xmmap.o xcrypt.o
 
diff --git a/openbsd-compat/strnlen.c b/openbsd-compat/strnlen.c
new file mode 100644
index 000000000..93d515595
--- /dev/null
+++ b/openbsd-compat/strnlen.c
@@ -0,0 +1,37 @@
+/*	$OpenBSD: strnlen.c,v 1.3 2010/06/02 12:58:12 millert Exp $	*/
+
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* OPENBSD ORIGINAL: lib/libc/string/strnlen.c */
+
+#include "config.h"
+#ifndef HAVE_STRNLEN
+#include <sys/types.h>
+
+#include <string.h>
+
+size_t
+strnlen(const char *str, size_t maxlen)
+{
+	const char *cp;
+
+	for (cp = str; maxlen != 0 && *cp != '\0'; cp++, maxlen--)
+		;
+
+	return (size_t)(cp - str);
+}
+#endif