Merge conflicts.

1 files changed, 575 insertions, 263 deletions

diff --git a/crypto/openssh/configure.ac b/crypto/openssh/configure.ac
index 5258d63..9a1b7e2 100644
--- a/crypto/openssh/configure.ac
+++ b/crypto/openssh/configure.ac
@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.292 2005/08/31 16:59:49 tim Exp $
+# $Id: configure.ac,v 1.322 2006/01/29 13:22:39 dtucker Exp $
 # $FreeBSD$
 #
 # Copyright (c) 1999-2004 Damien Miller
@@ -48,6 +48,11 @@ AC_PATH_PROG(PATH_GROUPADD_PROG, groupadd, groupadd,
 AC_PATH_PROG(PATH_USERADD_PROG, useradd, useradd,
 	[/usr/sbin${PATH_SEPARATOR}/etc])
 AC_CHECK_PROG(MAKE_PACKAGE_SUPPORTED, pkgmk, yes, no)
+if test -x /sbin/sh; then
+	AC_SUBST(STARTUP_SCRIPT_SHELL,/sbin/sh)
+else
+	AC_SUBST(STARTUP_SCRIPT_SHELL,/bin/sh)
+fi
 
 # System features
 AC_SYS_LARGEFILE
@@ -58,7 +63,9 @@ fi
 
 # Use LOGIN_PROGRAM from environment if possible
 if test ! -z "$LOGIN_PROGRAM" ; then
-	AC_DEFINE_UNQUOTED(LOGIN_PROGRAM_FALLBACK, "$LOGIN_PROGRAM")
+	AC_DEFINE_UNQUOTED(LOGIN_PROGRAM_FALLBACK, "$LOGIN_PROGRAM",
+		[If your header files don't define LOGIN_PROGRAM,
+		then use this (detected) from environment and PATH])
 else
 	# Search for login
 	AC_PATH_PROG(LOGIN_PROGRAM_FALLBACK, login)
@@ -69,7 +76,8 @@ fi
 
 AC_PATH_PROG(PATH_PASSWD_PROG, passwd)
 if test ! -z "$PATH_PASSWD_PROG" ; then
-	AC_DEFINE_UNQUOTED(_PATH_PASSWD_PROG, "$PATH_PASSWD_PROG")
+	AC_DEFINE_UNQUOTED(_PATH_PASSWD_PROG, "$PATH_PASSWD_PROG",
+		[Full path of your "passwd" program])
 fi
 
 if test -z "$LD" ; then
@@ -83,12 +91,14 @@ AC_CHECK_DECL(LLONG_MAX, have_llong_max=1, , [#include <limits.h>])
 
 if test "$GCC" = "yes" || test "$GCC" = "egcs"; then
 	CFLAGS="$CFLAGS -Wall -Wpointer-arith -Wuninitialized"
-	GCC_VER=`$CC --version`
+	GCC_VER=`$CC -v 2>&1 | $AWK '/gcc version /{print $3}'`
 	case $GCC_VER in
 		1.*) ;;
 		2.8* | 2.9*) CFLAGS="$CFLAGS -Wsign-compare" ;;
 		2.*) ;;
-		*) CFLAGS="$CFLAGS -Wsign-compare" ;;
+		3.*) CFLAGS="$CFLAGS -Wsign-compare" ;;
+		4.*) CFLAGS="$CFLAGS -Wsign-compare -Wno-pointer-sign" ;;
+		*) ;;
 	esac
 
 	if test -z "$have_llong_max"; then
@@ -104,70 +114,6 @@ if test "$GCC" = "yes" || test "$GCC" = "egcs"; then
 	fi
 fi
 
-if test -z "$have_llong_max"; then
-	AC_MSG_CHECKING([for max value of long long])
-	AC_RUN_IFELSE(
-		[AC_LANG_SOURCE([[
-#include <stdio.h>
-/* Why is this so damn hard? */
-#ifdef __GNUC__
-# undef __GNUC__
-#endif
-#define __USE_ISOC99
-#include <limits.h>
-#define DATA "conftest.llminmax"
-int main(void) {
-	FILE *f;
-	long long i, llmin, llmax = 0;
-
-	if((f = fopen(DATA,"w")) == NULL)
-		exit(1);
-
-#if defined(LLONG_MIN) && defined(LLONG_MAX)
-	fprintf(stderr, "Using system header for LLONG_MIN and LLONG_MAX\n");
-	llmin = LLONG_MIN;
-	llmax = LLONG_MAX;
-#else
-	fprintf(stderr, "Calculating  LLONG_MIN and LLONG_MAX\n");
-	/* This will work on one's complement and two's complement */
-	for (i = 1; i > llmax; i <<= 1, i++)
-		llmax = i;
-	llmin = llmax + 1LL;	/* wrap */
-#endif
-
-	/* Sanity check */
-	if (llmin + 1 < llmin || llmin - 1 < llmin || llmax + 1 > llmax
-	    || llmax - 1 > llmax) {
-		fprintf(f, "unknown unknown\n");
-		exit(2);
-	}
-
-	if (fprintf(f ,"%lld %lld", llmin, llmax) < 0)
-		exit(3);
-
-	exit(0);
-}
-		]])],
-		[
-			llong_min=`$AWK '{print $1}' conftest.llminmax`
-			llong_max=`$AWK '{print $2}' conftest.llminmax`
-			AC_MSG_RESULT($llong_max)
-			AC_DEFINE_UNQUOTED(LLONG_MAX, [${llong_max}LL],
-			    [max value of long long calculated by configure])
-			AC_MSG_CHECKING([for min value of long long])
-			AC_MSG_RESULT($llong_min)
-			AC_DEFINE_UNQUOTED(LLONG_MIN, [${llong_min}LL],
-			    [min value of long long calculated by configure])
-		],
-		[
-			AC_MSG_RESULT(not found)
-		],
-		[
-			AC_MSG_WARN([cross compiling: not checking])
-		]
-	)
-fi
-
 AC_ARG_WITH(rpath,
 	[  --without-rpath         Disable auto-added -R linker paths],
 	[
@@ -202,7 +148,8 @@ case "$host" in
 	fi
 	LDFLAGS="$saved_LDFLAGS"
 	dnl Check for authenticate.  Might be in libs.a on older AIXes
-	AC_CHECK_FUNC(authenticate, [AC_DEFINE(WITH_AIXAUTHENTICATE)],
+	AC_CHECK_FUNC(authenticate, [AC_DEFINE(WITH_AIXAUTHENTICATE, 1,
+		[Define if you want to enable AIX4's authenticate function])],
 		[AC_CHECK_LIB(s,authenticate,
 			[ AC_DEFINE(WITH_AIXAUTHENTICATE)
 				LIBS="$LIBS -ls"
@@ -218,7 +165,9 @@ case "$host" in
 			[#include <usersec.h>],
 			[(void)loginfailed("user","host","tty",0);],
 			[AC_MSG_RESULT(yes)
-			 AC_DEFINE(AIX_LOGINFAILED_4ARG)],
+			 AC_DEFINE(AIX_LOGINFAILED_4ARG, 1,
+				[Define if your AIX loginfailed() function
+				takes 4 arguments (AIX >= 5.2)])],
 			[AC_MSG_RESULT(no)]
 		)],
 		[],
@@ -226,25 +175,38 @@ case "$host" in
 	)
 	AC_CHECK_FUNCS(setauthdb)
 	check_for_aix_broken_getaddrinfo=1
-	AC_DEFINE(BROKEN_REALPATH)
-	AC_DEFINE(SETEUID_BREAKS_SETUID)
-	AC_DEFINE(BROKEN_SETREUID)
-	AC_DEFINE(BROKEN_SETREGID)
+	AC_DEFINE(BROKEN_REALPATH, 1, [Define if you have a broken realpath.])
+	AC_DEFINE(SETEUID_BREAKS_SETUID, 1,
+	    [Define if your platform breaks doing a seteuid before a setuid])
+	AC_DEFINE(BROKEN_SETREUID, 1, [Define if your setreuid() is broken])
+	AC_DEFINE(BROKEN_SETREGID, 1, [Define if your setregid() is broken])
 	dnl AIX handles lastlog as part of its login message
-	AC_DEFINE(DISABLE_LASTLOG)
-	AC_DEFINE(LOGIN_NEEDS_UTMPX)
-	AC_DEFINE(SPT_TYPE,SPT_REUSEARGV)
+	AC_DEFINE(DISABLE_LASTLOG, 1, [Define if you don't want to use lastlog])
+	AC_DEFINE(LOGIN_NEEDS_UTMPX, 1,
+		[Some systems need a utmpx entry for /bin/login to work])
+	AC_DEFINE(SPT_TYPE,SPT_REUSEARGV,
+		[Define to a Set Process Title type if your system is
+		supported by bsd-setproctitle.c])
+	AC_DEFINE(SSHPAM_CHAUTHTOK_NEEDS_RUID, 1,
+	    [AIX 5.2 and 5.3 (and presumably newer) require this])
 	;;
 *-*-cygwin*)
 	check_for_libcrypt_later=1
 	LIBS="$LIBS /usr/lib/textmode.o"
-	AC_DEFINE(HAVE_CYGWIN)
-	AC_DEFINE(USE_PIPES)
-	AC_DEFINE(DISABLE_SHADOW)
-	AC_DEFINE(IP_TOS_IS_BROKEN)
-	AC_DEFINE(NO_X11_UNIX_SOCKETS)
-	AC_DEFINE(NO_IPPORT_RESERVED_CONCEPT)
-	AC_DEFINE(DISABLE_FD_PASSING)
+	AC_DEFINE(HAVE_CYGWIN, 1, [Define if you are on Cygwin])
+	AC_DEFINE(USE_PIPES, 1, [Use PIPES instead of a socketpair()])
+	AC_DEFINE(DISABLE_SHADOW, 1,
+		[Define if you want to disable shadow passwords])
+	AC_DEFINE(IP_TOS_IS_BROKEN, 1,
+		[Define if your system choked on IP TOS setting])
+	AC_DEFINE(NO_X11_UNIX_SOCKETS, 1,
+		[Define if X11 doesn't support AF_UNIX sockets on that system])
+	AC_DEFINE(NO_IPPORT_RESERVED_CONCEPT, 1,
+		[Define if the concept of ports only accessible to
+		superusers isn't known])
+	AC_DEFINE(DISABLE_FD_PASSING, 1,
+		[Define if your platform needs to skip post auth
+		file descriptor passing])
 	;;
 *-*-dgux*)
 	AC_DEFINE(IP_TOS_IS_BROKEN)
@@ -261,22 +223,26 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
 		exit(1);
 }], [AC_MSG_RESULT(working)],
 	[AC_MSG_RESULT(buggy)
-	AC_DEFINE(BROKEN_GETADDRINFO)],
+	AC_DEFINE(BROKEN_GETADDRINFO, 1, [getaddrinfo is broken (if present)])],
 	[AC_MSG_RESULT(assume it is working)])
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
-	AC_DEFINE_UNQUOTED(BIND_8_COMPAT, 1)
+	AC_DEFINE_UNQUOTED(BIND_8_COMPAT, 1,
+		[Define if your resolver libs need this for getrrsetbyname])
 	;;
 *-*-hpux*)
 	# first we define all of the options common to all HP-UX releases
 	CPPFLAGS="$CPPFLAGS -D_HPUX_SOURCE -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED=1"
 	IPADDR_IN_DISPLAY=yes
 	AC_DEFINE(USE_PIPES)
-	AC_DEFINE(LOGIN_NO_ENDOPT)
+	AC_DEFINE(LOGIN_NO_ENDOPT, 1,
+	    [Define if your login program cannot handle end of options ("--")])
 	AC_DEFINE(LOGIN_NEEDS_UTMPX)
-	AC_DEFINE(LOCKED_PASSWD_STRING, "*")
+	AC_DEFINE(LOCKED_PASSWD_STRING, "*",
+		[String used in /etc/passwd to denote locked account])
 	AC_DEFINE(SPT_TYPE,SPT_PSTAT)
+	MAIL="/var/mail/username"
 	LIBS="$LIBS -lsec"
 	AC_CHECK_LIB(xnet, t_error, ,
 	    AC_MSG_ERROR([*** -lxnet needed on HP-UX - check config.log ***]))
@@ -289,8 +255,12 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
 		fi
 		;;
 	*-*-hpux11*)
-		AC_DEFINE(PAM_SUN_CODEBASE)
-		AC_DEFINE(DISABLE_UTMP)
+		AC_DEFINE(PAM_SUN_CODEBASE, 1,
+			[Define if you are using Solaris-derived PAM which
+			passes pam_messages to the conversation function
+			with an extra level of indirection])
+		AC_DEFINE(DISABLE_UTMP, 1,
+			[Define if you don't want to use utmp])
 		AC_DEFINE(USE_BTMP, 1, [Use btmp to log bad logins])
 		check_for_hpux_broken_getaddrinfo=1
 		check_for_conflicting_getspnam=1
@@ -300,7 +270,9 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
 	# lastly, we define options specific to minor releases
 	case "$host" in
 	*-*-hpux10.26)
-		AC_DEFINE(HAVE_SECUREWARE)
+		AC_DEFINE(HAVE_SECUREWARE, 1,
+			[Define if you have SecureWare-based
+			protected password database])
 		disable_ptmx_check=yes
 		LIBS="$LIBS -lsecpw"
 		;;
@@ -308,24 +280,33 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
 	;;
 *-*-irix5*)
 	PATH="$PATH:/usr/etc"
-	AC_DEFINE(BROKEN_INET_NTOA)
+	AC_DEFINE(BROKEN_INET_NTOA, 1,
+		[Define if you system's inet_ntoa is busted
+		(e.g. Irix gcc issue)])
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
-	AC_DEFINE(WITH_ABBREV_NO_TTY)
+	AC_DEFINE(WITH_ABBREV_NO_TTY, 1,
+		[Define if you shouldn't strip 'tty' from your
+		ttyname in [uw]tmp])
 	AC_DEFINE(LOCKED_PASSWD_STRING, "*LK*")
 	;;
 *-*-irix6*)
 	PATH="$PATH:/usr/etc"
-	AC_DEFINE(WITH_IRIX_ARRAY)
-	AC_DEFINE(WITH_IRIX_PROJECT)
-	AC_DEFINE(WITH_IRIX_AUDIT)
-	AC_CHECK_FUNC(jlimit_startjob, [AC_DEFINE(WITH_IRIX_JOBS)])
+	AC_DEFINE(WITH_IRIX_ARRAY, 1,
+		[Define if you have/want arrays
+		(cluster-wide session managment, not C arrays)])
+	AC_DEFINE(WITH_IRIX_PROJECT, 1,
+		[Define if you want IRIX project management])
+	AC_DEFINE(WITH_IRIX_AUDIT, 1,
+		[Define if you want IRIX audit trails])
+	AC_CHECK_FUNC(jlimit_startjob, [AC_DEFINE(WITH_IRIX_JOBS, 1,
+		[Define if you want IRIX kernel jobs])])
 	AC_DEFINE(BROKEN_INET_NTOA)
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
-	AC_DEFINE(BROKEN_UPDWTMPX)
+	AC_DEFINE(BROKEN_UPDWTMPX, 1, [updwtmpx is broken (if present)])
 	AC_DEFINE(WITH_ABBREV_NO_TTY)
 	AC_DEFINE(LOCKED_PASSWD_STRING, "*LK*")
 	;;
@@ -333,22 +314,37 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
 	no_dev_ptmx=1
 	check_for_libcrypt_later=1
 	check_for_openpty_ctty_bug=1
-	AC_DEFINE(DONT_TRY_OTHER_AF)
-	AC_DEFINE(PAM_TTY_KLUDGE)
-	AC_DEFINE(LOCKED_PASSWD_PREFIX, "!")
+	AC_DEFINE(DONT_TRY_OTHER_AF, 1, [Workaround more Linux IPv6 quirks])
+	AC_DEFINE(PAM_TTY_KLUDGE, 1,
+		[Work around problematic Linux PAM modules handling of PAM_TTY])
+	AC_DEFINE(LOCKED_PASSWD_PREFIX, "!",
+		[String used in /etc/passwd to denote locked account])
 	AC_DEFINE(SPT_TYPE,SPT_REUSEARGV)
-	AC_DEFINE(LINK_OPNOTSUPP_ERRNO, EPERM)
+	AC_DEFINE(LINK_OPNOTSUPP_ERRNO, EPERM,
+		[Define to whatever link() returns for "not supported"
+		if it doesn't return EOPNOTSUPP.])
 	AC_DEFINE(_PATH_BTMP, "/var/log/btmp", [log for bad login attempts])
-	AC_DEFINE(USE_BTMP, 1, [Use btmp to log bad logins])
+	AC_DEFINE(USE_BTMP)
 	inet6_default_4in6=yes
 	case `uname -r` in
 	1.*|2.0.*)
-		AC_DEFINE(BROKEN_CMSG_TYPE)
+		AC_DEFINE(BROKEN_CMSG_TYPE, 1,
+			[Define if cmsg_type is not passed correctly])
 		;;
 	esac
+	# tun(4) forwarding compat code
+	AC_CHECK_HEADERS(linux/if_tun.h)
+	if test "x$ac_cv_header_linux_if_tun_h" = "xyes" ; then
+		AC_DEFINE(SSH_TUN_LINUX, 1,
+		    [Open tunnel devices the Linux tun/tap way])
+		AC_DEFINE(SSH_TUN_COMPAT_AF, 1,
+		    [Use tunnel device compatibility to OpenBSD])
+		AC_DEFINE(SSH_TUN_PREPEND_AF, 1,
+		    [Prepend the address family to IP tunnel traffic])
+	fi
 	;;
 mips-sony-bsd|mips-sony-newsos4)
-	AC_DEFINE(NEED_SETPRGP, [], [Need setpgrp to acquire controlling tty])
+	AC_DEFINE(NEED_SETPRGP, 1, [Need setpgrp to acquire controlling tty])
 	SONY=1
 	;;
 *-*-netbsd*)
@@ -356,9 +352,18 @@ mips-sony-bsd|mips-sony-newsos4)
 	if test "x$withval" != "xno" ; then
 		need_dash_r=1
 	fi
+	AC_DEFINE(SSH_TUN_FREEBSD, 1, [Open tunnel devices the FreeBSD way])
+	AC_CHECK_HEADER([net/if_tap.h], ,
+	    AC_DEFINE(SSH_TUN_NO_L2, 1, [No layer 2 tunnel support]))
+	AC_DEFINE(SSH_TUN_PREPEND_AF, 1,
+	    [Prepend the address family to IP tunnel traffic])
 	;;
 *-*-freebsd*)
 	check_for_libcrypt_later=1
+	AC_DEFINE(LOCKED_PASSWD_PREFIX, "*LOCKED*", [Account locked with pw(1)])
+	AC_DEFINE(SSH_TUN_FREEBSD, 1, [Open tunnel devices the FreeBSD way])
+	AC_CHECK_HEADER([net/if_tap.h], ,
+	    AC_DEFINE(SSH_TUN_NO_L2, 1, [No layer 2 tunnel support]))
 	;;
 *-*-bsdi*)
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
@@ -370,13 +375,15 @@ mips-sony-bsd|mips-sony-newsos4)
 	conf_utmp_location=/etc/utmp
 	conf_wtmp_location=/usr/adm/wtmp
 	MAIL=/usr/spool/mail
-	AC_DEFINE(HAVE_NEXT)
+	AC_DEFINE(HAVE_NEXT, 1, [Define if you are on NeXT])
 	AC_DEFINE(BROKEN_REALPATH)
 	AC_DEFINE(USE_PIPES)
-	AC_DEFINE(BROKEN_SAVED_UIDS)
+	AC_DEFINE(BROKEN_SAVED_UIDS, 1, [Needed for NeXT])
 	;;
 *-*-openbsd*)
 	AC_DEFINE(HAVE_ATTRIBUTE__SENTINEL__, 1, [OpenBSD's gcc has sentinel])
+	AC_DEFINE(HAVE_ATTRIBUTE__BOUNDED__, 1, [OpenBSD's gcc has bounded])
+	AC_DEFINE(SSH_TUN_OPENBSD, 1, [Open tunnel devices the OpenBSD way])
 	;;
 *-*-solaris*)
 	if test "x$withval" != "xno" ; then
@@ -384,12 +391,18 @@ mips-sony-bsd|mips-sony-newsos4)
 	fi
 	AC_DEFINE(PAM_SUN_CODEBASE)
 	AC_DEFINE(LOGIN_NEEDS_UTMPX)
-	AC_DEFINE(LOGIN_NEEDS_TERM)
+	AC_DEFINE(LOGIN_NEEDS_TERM, 1,
+		[Some versions of /bin/login need the TERM supplied
+		on the commandline])
 	AC_DEFINE(PAM_TTY_KLUDGE)
-	AC_DEFINE(SSHPAM_CHAUTHTOK_NEEDS_RUID)
+	AC_DEFINE(SSHPAM_CHAUTHTOK_NEEDS_RUID, 1,
+		[Define if pam_chauthtok wants real uid set
+		to the unpriv'ed user])
 	AC_DEFINE(LOCKED_PASSWD_STRING, "*LK*")
 	# Pushing STREAMS modules will cause sshd to acquire a controlling tty.
-	AC_DEFINE(SSHD_ACQUIRES_CTTY)
+	AC_DEFINE(SSHD_ACQUIRES_CTTY, 1,
+		[Define if sshd somehow reacquires a controlling TTY
+		after setsid()])
 	external_path_file=/etc/default/login
 	# hardwire lastlog location (can't detect it on some versions)
 	conf_lastlog_location="/var/adm/lastlog"
@@ -398,7 +411,8 @@ mips-sony-bsd|mips-sony-newsos4)
 	if test "$sol2ver" -ge 8; then
 		AC_MSG_RESULT(yes)
 		AC_DEFINE(DISABLE_UTMP)
-		AC_DEFINE(DISABLE_WTMP)
+		AC_DEFINE(DISABLE_WTMP, 1,
+			[Define if you don't want to use wtmp])
 	else
 		AC_MSG_RESULT(no)
 	fi
@@ -423,8 +437,8 @@ mips-sony-bsd|mips-sony-newsos4)
 *-sni-sysv*)
 	# /usr/ucblib MUST NOT be searched on ReliantUNIX
 	AC_CHECK_LIB(dl, dlsym, ,)
-	# -lresolv needs to be at then end of LIBS or DNS lookups break
-	AC_CHECK_LIB(res_query, resolv, [ LIBS="$LIBS -lresolv" ])
+	# -lresolv needs to be at the end of LIBS or DNS lookups break
+	AC_CHECK_LIB(resolv, res_query, [ LIBS="$LIBS -lresolv" ])
 	IPADDR_IN_DISPLAY=yes
 	AC_DEFINE(USE_PIPES)
 	AC_DEFINE(IP_TOS_IS_BROKEN)
@@ -439,11 +453,13 @@ mips-sony-bsd|mips-sony-newsos4)
 	;;
 # UnixWare 1.x, UnixWare 2.x, and others based on code from Univel.
 *-*-sysv4.2*)
+	CFLAGS="$CFLAGS -Dva_list=_VA_LIST"
 	AC_DEFINE(USE_PIPES)
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
 	AC_DEFINE(PASSWD_NEEDS_USERNAME, 1, [must supply username to passwd])
+	AC_DEFINE(LOCKED_PASSWD_STRING, "*LK*")
 	;;
 # UnixWare 7.x, OpenUNIX 8
 *-*-sysv5*)
@@ -453,11 +469,14 @@ mips-sony-bsd|mips-sony-newsos4)
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
-	AC_DEFINE(PASSWD_NEEDS_USERNAME, 1, [must supply username to passwd])
+	AC_DEFINE(PASSWD_NEEDS_USERNAME)
 	case "$host" in
 	*-*-sysv5SCO_SV*)	# SCO OpenServer 6.x
 		TEST_SHELL=/u95/bin/sh
-		AC_DEFINE(BROKEN_LIBIAF, 1, [ia_uinfo routines not supported by OS yet])
+		AC_DEFINE(BROKEN_LIBIAF, 1,
+			[ia_uinfo routines not supported by OS yet])
+		;;
+	*)	AC_DEFINE(LOCKED_PASSWD_STRING, "*LK*")
 		;;
 	esac
 	;;
@@ -483,13 +502,14 @@ mips-sony-bsd|mips-sony-newsos4)
 	AC_DEFINE(BROKEN_SETREGID)
 	AC_DEFINE(WITH_ABBREV_NO_TTY)
 	AC_DEFINE(BROKEN_UPDWTMPX)
-	AC_DEFINE(PASSWD_NEEDS_USERNAME, 1, [must supply username to passwd])
+	AC_DEFINE(PASSWD_NEEDS_USERNAME)
 	AC_CHECK_FUNCS(getluid setluid)
 	MANTYPE=man
 	TEST_SHELL=ksh
 	;;
 *-*-unicosmk*)
-	AC_DEFINE(NO_SSH_LASTLOG)
+	AC_DEFINE(NO_SSH_LASTLOG, 1,
+		[Define if you don't want to use lastlog in session.c])
 	AC_DEFINE(SETEUID_BREAKS_SETUID)
 	AC_DEFINE(BROKEN_SETREUID)
 	AC_DEFINE(BROKEN_SETREGID)
@@ -536,13 +556,18 @@ mips-sony-bsd|mips-sony-newsos4)
 	if test -z "$no_osfsia" ; then
 		if test -f /etc/sia/matrix.conf; then
 			AC_MSG_RESULT(yes)
-			AC_DEFINE(HAVE_OSF_SIA)
-			AC_DEFINE(DISABLE_LOGIN)
+			AC_DEFINE(HAVE_OSF_SIA, 1,
+				[Define if you have Digital Unix Security
+				Integration Architecture])
+			AC_DEFINE(DISABLE_LOGIN, 1,
+				[Define if you don't want to use your
+				system's login() call])
 			AC_DEFINE(DISABLE_FD_PASSING)
 			LIBS="$LIBS -lsecurity -ldb -lm -laud"
 		else
 			AC_MSG_RESULT(no)
-			AC_DEFINE(LOCKED_PASSWD_SUBSTR, "Nologin")
+			AC_DEFINE(LOCKED_PASSWD_SUBSTR, "Nologin",
+			  [String used in /etc/passwd to denote locked account])
 		fi
 	fi
 	AC_DEFINE(BROKEN_GETADDRINFO)
@@ -554,21 +579,21 @@ mips-sony-bsd|mips-sony-newsos4)
 *-*-nto-qnx)
 	AC_DEFINE(USE_PIPES)
 	AC_DEFINE(NO_X11_UNIX_SOCKETS)
-	AC_DEFINE(MISSING_NFDBITS)
-	AC_DEFINE(MISSING_HOWMANY)
-	AC_DEFINE(MISSING_FD_MASK)
+	AC_DEFINE(MISSING_NFDBITS, 1, [Define on *nto-qnx systems])
+	AC_DEFINE(MISSING_HOWMANY, 1, [Define on *nto-qnx systems])
+	AC_DEFINE(MISSING_FD_MASK, 1, [Define on *nto-qnx systems])
 	;;
 
 *-*-ultrix*)
-	AC_DEFINE(BROKEN_GETGROUPS, [], [getgroups(0,NULL) will return -1])
-	AC_DEFINE(BROKEN_MMAP, [], [Ultrix mmap can't map files])
-	AC_DEFINE(NEED_SETPRGP, [], [Need setpgrp to acquire controlling tty])
+	AC_DEFINE(BROKEN_GETGROUPS, 1, [getgroups(0,NULL) will return -1])
+	AC_DEFINE(BROKEN_MMAP, 1, [Ultrix mmap can't map files])
+	AC_DEFINE(NEED_SETPRGP)
 	AC_DEFINE(HAVE_SYS_SYSLOG_H, 1, [Force use of sys/syslog.h on Ultrix])
 	;;
 
 *-*-lynxos)
         CFLAGS="$CFLAGS -D__NO_INCLUDE_WARN__"
-        AC_DEFINE(MISSING_HOWMANY)
+	AC_DEFINE(MISSING_HOWMANY)
         AC_DEFINE(BROKEN_SETVBUF, 1, [LynxOS has broken setvbuf() implementation])
         ;;
 esac
@@ -615,7 +640,7 @@ AC_ARG_WITH(Werror,
 	[
 		if test -n "$withval"  &&  test "x$withval" != "xno"; then
 			werror_flags="-Werror"
-			if "x${withval}" != "xyes"; then
+			if test "x${withval}" != "xyes"; then
 				werror_flags="$withval"
 			fi
 		fi
@@ -654,6 +679,7 @@ AC_CHECK_HEADERS( \
 	login_cap.h \
 	maillock.h \
 	ndir.h \
+	net/if.h \
 	netdb.h \
 	netgroup.h \
 	netinet/in_systm.h \
@@ -716,8 +742,8 @@ AC_CHECK_FUNCS(dirname, [AC_CHECK_HEADERS(libgen.h)] ,[
 			ac_cv_have_broken_dirname, [
 			save_LIBS="$LIBS"
 			LIBS="$LIBS -lgen"
-			AC_TRY_RUN(
-				[
+			AC_RUN_IFELSE(
+				[AC_LANG_SOURCE([[
 #include <libgen.h>
 #include <string.h>
 
@@ -732,9 +758,10 @@ int main(int argc, char **argv) {
 	exit(0);
     }
 }
-				],
+				]])],
+				[ ac_cv_have_broken_dirname="no" ],
+				[ ac_cv_have_broken_dirname="yes" ],
 				[ ac_cv_have_broken_dirname="no" ],
-				[ ac_cv_have_broken_dirname="yes" ]
 			)
 			LIBS="$save_LIBS"
 		])
@@ -748,7 +775,8 @@ int main(int argc, char **argv) {
 
 AC_CHECK_FUNC(getspnam, ,
 	AC_CHECK_LIB(gen, getspnam, LIBS="$LIBS -lgen"))
-AC_SEARCH_LIBS(basename, gen, AC_DEFINE(HAVE_BASENAME))
+AC_SEARCH_LIBS(basename, gen, AC_DEFINE(HAVE_BASENAME, 1,
+	[Define if you have the basename function.]))
 
 dnl zlib is required
 AC_ARG_WITH(zlib,
@@ -852,14 +880,15 @@ dnl UnixWare 2.x
 AC_CHECK_FUNC(strcasecmp,
 	[], [ AC_CHECK_LIB(resolv, strcasecmp, LIBS="$LIBS -lresolv") ]
 )
-AC_CHECK_FUNC(utimes,
+AC_CHECK_FUNCS(utimes,
 	[], [ AC_CHECK_LIB(c89, utimes, [AC_DEFINE(HAVE_UTIMES)
 					LIBS="$LIBS -lc89"]) ]
 )
 
 dnl    Checks for libutil functions
 AC_CHECK_HEADERS(libutil.h)
-AC_SEARCH_LIBS(login, util bsd, [AC_DEFINE(HAVE_LOGIN)])
+AC_SEARCH_LIBS(login, util bsd, [AC_DEFINE(HAVE_LOGIN, 1,
+	[Define if your libraries define login()])])
 AC_CHECK_FUNCS(logout updwtmp logwtmp)
 
 AC_FUNC_STRFTIME
@@ -874,7 +903,9 @@ AC_EGREP_CPP(FOUNDIT,
 		#endif
 	],
 	[
-		AC_DEFINE(GLOB_HAS_ALTDIRFUNC)
+		AC_DEFINE(GLOB_HAS_ALTDIRFUNC, 1,
+			[Define if your system glob() function has
+			the GLOB_ALTDIRFUNC extension])
 		AC_MSG_RESULT(yes)
 	],
 	[
@@ -890,7 +921,9 @@ AC_EGREP_CPP(FOUNDIT,
 		int main(void){glob_t g; g.gl_matchc = 1;}
 	],
 	[
-		AC_DEFINE(GLOB_HAS_GL_MATCHC)
+		AC_DEFINE(GLOB_HAS_GL_MATCHC, 1,
+			[Define if your system glob() function has
+			gl_matchc options in glob_t])
 		AC_MSG_RESULT(yes)
 	],
 	[
@@ -908,7 +941,9 @@ int main(void){struct dirent d;exit(sizeof(d.d_name)<=sizeof(char));}
 	[AC_MSG_RESULT(yes)],
 	[
 		AC_MSG_RESULT(no)
-		AC_DEFINE(BROKEN_ONE_BYTE_DIRENT_D_NAME)
+		AC_DEFINE(BROKEN_ONE_BYTE_DIRENT_D_NAME, 1,
+			[Define if your struct dirent expects you to
+			allocate extra space for d_name])
 	],
 	[
 		AC_MSG_WARN([cross compiling: assuming BROKEN_ONE_BYTE_DIRENT_D_NAME])
@@ -918,7 +953,7 @@ int main(void){struct dirent d;exit(sizeof(d.d_name)<=sizeof(char));}
 
 AC_MSG_CHECKING([for /proc/pid/fd directory])
 if test -d "/proc/$$/fd" ; then
-	AC_DEFINE(HAVE_PROC_PID)
+	AC_DEFINE(HAVE_PROC_PID, 1, [Define if you have /proc/$pid/fd])
 	AC_MSG_RESULT(yes)
 else
 	AC_MSG_RESULT(no)
@@ -936,17 +971,17 @@ AC_ARG_WITH(skey,
 				LDFLAGS="$LDFLAGS -L${withval}/lib"
 			fi
 
-			AC_DEFINE(SKEY)
+			AC_DEFINE(SKEY, 1, [Define if you want S/Key support])
 			LIBS="-lskey $LIBS"
 			SKEY_MSG="yes"
 
 			AC_MSG_CHECKING([for s/key support])
-			AC_TRY_RUN(
-				[
+			AC_LINK_IFELSE(
+				[AC_LANG_SOURCE([[
 #include <stdio.h>
 #include <skey.h>
 int main() { char *ff = skey_keyinfo(""); ff=""; exit(0); }
-				],
+				]])],
 				[AC_MSG_RESULT(yes)],
 				[
 					AC_MSG_RESULT(no)
@@ -958,7 +993,9 @@ int main() { char *ff = skey_keyinfo(""); ff=""; exit(0); }
 				 #include <skey.h>],
 				[(void)skeychallenge(NULL,"name","",0);],
 				[AC_MSG_RESULT(yes)
-				 AC_DEFINE(SKEYCHALLENGE_4ARG)],
+				 AC_DEFINE(SKEYCHALLENGE_4ARG, 1,
+					[Define if your skeychallenge()
+					function takes 4 arguments (NetBSD)])],
 				[AC_MSG_RESULT(no)]
         		)
 		fi
@@ -978,8 +1015,8 @@ AC_ARG_WITH(opie,
 				LDFLAGS="$LDFLAGS -L${withval}/lib"
 			fi
 
-			AC_DEFINE(SKEY)
-			AC_DEFINE(OPIE)
+			AC_DEFINE(SKEY, 1, [Define if you want S/Key support])
+			AC_DEFINE(OPIE, 1, [Define if S/Key is actually OPIE])
 			LIBS="-lopie $LIBS"
 			OPIE_MSG="yes" 
 	
@@ -1044,7 +1081,9 @@ AC_ARG_WITH(tcp-wrappers,
 				[hosts_access(0);],
 				[
 					AC_MSG_RESULT(yes)
-					AC_DEFINE(LIBWRAP)
+					AC_DEFINE(LIBWRAP, 1,
+						[Define if you want
+						TCP Wrappers support])
 					AC_SUBST(LIBWRAP)
 					TCPW_MSG="yes"
 				],
@@ -1063,11 +1102,15 @@ AC_ARG_WITH(libedit,
 	[  --with-libedit[[=PATH]]   Enable libedit support for sftp],
 	[ if test "x$withval" != "xno" ; then
 		if test "x$withval" != "xyes"; then
-			CPPFLAGS="$CPPFLAGS -I$withval/include"
-			LDFLAGS="$LDFLAGS -L$withval/lib"
+			CPPFLAGS="$CPPFLAGS -I${withval}/include"
+			if test -n "${need_dash_r}"; then
+				LDFLAGS="-L${withval}/lib -R${withval}/lib ${LDFLAGS}"
+			else
+				LDFLAGS="-L${withval}/lib ${LDFLAGS}"
+			fi
 		fi
 		AC_CHECK_LIB(edit, el_init,
-			[ AC_DEFINE(USE_LIBEDIT, [], [Use libedit for sftp])
+			[ AC_DEFINE(USE_LIBEDIT, 1, [Use libedit for sftp])
 			  LIBEDIT="-ledit -lcurses"
 			  LIBEDIT_MSG="yes"
 			  AC_SUBST(LIBEDIT)
@@ -1111,12 +1154,12 @@ AC_ARG_WITH(audit,
 		    [AC_MSG_ERROR(BSM enabled and required function not found)])
 		# These are optional
 		AC_CHECK_FUNCS(getaudit_addr)
-		AC_DEFINE(USE_BSM_AUDIT, [], [Use BSM audit module])
+		AC_DEFINE(USE_BSM_AUDIT, 1, [Use BSM audit module])
 		;;
 	  debug)
 		AUDIT_MODULE=debug
 		AC_MSG_RESULT(debug)
-		AC_DEFINE(SSH_AUDIT_EVENTS, [], Use audit debugging module)
+		AC_DEFINE(SSH_AUDIT_EVENTS, 1, Use audit debugging module)
 		;;
 	  no)
 		AC_MSG_RESULT(no)
@@ -1130,6 +1173,7 @@ AC_ARG_WITH(audit,
 dnl    Checks for library functions. Please keep in alphabetical order
 AC_CHECK_FUNCS( \
 	arc4random \
+	asprintf \
 	b64_ntop \
 	__b64_ntop \
 	b64_pton \
@@ -1205,7 +1249,7 @@ AC_CHECK_FUNCS( \
 	truncate \
 	unsetenv \
 	updwtmpx \
-	utimes \
+	vasprintf \
 	vhangup \
 	vsnprintf \
 	waitpid \
@@ -1226,7 +1270,8 @@ str = gai_strerror(0);],[
 		AC_DEFINE(HAVE_CONST_GAI_STRERROR_PROTO, 1,
 		[Define if gai_strerror() returns const char *])])])
 
-AC_SEARCH_LIBS(nanosleep, rt posix4, AC_DEFINE(HAVE_NANOSLEEP))
+AC_SEARCH_LIBS(nanosleep, rt posix4, AC_DEFINE(HAVE_NANOSLEEP, 1,
+	[Some systems put nanosleep outside of libc]))
 
 dnl Make sure prototypes are defined for these before using them.
 AC_CHECK_DECL(getrusage, [AC_CHECK_FUNCS(getrusage)])
@@ -1258,7 +1303,8 @@ AC_CHECK_FUNCS(setresuid, [
 int main(){errno=0; setresuid(0,0,0); if (errno==ENOSYS) exit(1); else exit(0);}
 		]])],
 		[AC_MSG_RESULT(yes)],
-		[AC_DEFINE(BROKEN_SETRESUID)
+		[AC_DEFINE(BROKEN_SETRESUID, 1,
+			[Define if your setresuid() is broken])
 		 AC_MSG_RESULT(not implemented)],
 		[AC_MSG_WARN([cross compiling: not checking setresuid])]
 	)
@@ -1274,7 +1320,8 @@ AC_CHECK_FUNCS(setresgid, [
 int main(){errno=0; setresgid(0,0,0); if (errno==ENOSYS) exit(1); else exit(0);}
 		]])],
 		[AC_MSG_RESULT(yes)],
-		[AC_DEFINE(BROKEN_SETRESGID)
+		[AC_DEFINE(BROKEN_SETRESGID, 1,
+			[Define if your setresgid() is broken])
 		 AC_MSG_RESULT(not implemented)],
 		[AC_MSG_WARN([cross compiling: not checking setresuid])]
 	)
@@ -1290,13 +1337,16 @@ AC_CHECK_FUNCS(endutxent getutxent getutxid getutxline pututxline )
 AC_CHECK_FUNCS(setutxent utmpxname)
 
 AC_CHECK_FUNC(daemon,
-	[AC_DEFINE(HAVE_DAEMON)],
-	[AC_CHECK_LIB(bsd, daemon, [LIBS="$LIBS -lbsd"; AC_DEFINE(HAVE_DAEMON)])]
+	[AC_DEFINE(HAVE_DAEMON, 1, [Define if your libraries define daemon()])],
+	[AC_CHECK_LIB(bsd, daemon,
+		[LIBS="$LIBS -lbsd"; AC_DEFINE(HAVE_DAEMON)])]
 )
 
 AC_CHECK_FUNC(getpagesize,
-	[AC_DEFINE(HAVE_GETPAGESIZE)],
-	[AC_CHECK_LIB(ucb, getpagesize, [LIBS="$LIBS -lucb"; AC_DEFINE(HAVE_GETPAGESIZE)])]
+	[AC_DEFINE(HAVE_GETPAGESIZE, 1,
+		[Define if your libraries define getpagesize()])],
+	[AC_CHECK_LIB(ucb, getpagesize,
+		[LIBS="$LIBS -lucb"; AC_DEFINE(HAVE_GETPAGESIZE)])]
 )
 
 # Check for broken snprintf
@@ -1310,13 +1360,62 @@ int main(void){char b[5];snprintf(b,5,"123456789");exit(b[4]!='\0');}
 		[AC_MSG_RESULT(yes)],
 		[
 			AC_MSG_RESULT(no)
-			AC_DEFINE(BROKEN_SNPRINTF)
+			AC_DEFINE(BROKEN_SNPRINTF, 1,
+				[Define if your snprintf is busted])
 			AC_MSG_WARN([****** Your snprintf() function is broken, complain to your vendor])
 		],
 		[ AC_MSG_WARN([cross compiling: Assuming working snprintf()]) ]
 	)
 fi
 
+# If we don't have a working asprintf, then we strongly depend on vsnprintf
+# returning the right thing on overflow: the number of characters it tried to
+# create (as per SUSv3)
+if test "x$ac_cv_func_asprintf" != "xyes" && \
+   test "x$ac_cv_func_vsnprintf" = "xyes" ; then
+	AC_MSG_CHECKING([whether vsnprintf returns correct values on overflow])
+	AC_RUN_IFELSE(
+		[AC_LANG_SOURCE([[
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+int x_snprintf(char *str,size_t count,const char *fmt,...)
+{
+	size_t ret; va_list ap;
+	va_start(ap, fmt); ret = vsnprintf(str, count, fmt, ap); va_end(ap);
+	return ret;
+}
+int main(void)
+{
+	char x[1];
+	exit(x_snprintf(x, 1, "%s %d", "hello", 12345) == 11 ? 0 : 1);
+} ]])],
+		[AC_MSG_RESULT(yes)],
+		[
+			AC_MSG_RESULT(no)
+			AC_DEFINE(BROKEN_SNPRINTF, 1,
+				[Define if your snprintf is busted])
+			AC_MSG_WARN([****** Your vsnprintf() function is broken, complain to your vendor])
+		],
+		[ AC_MSG_WARN([cross compiling: Assuming working vsnprintf()]) ]
+	)
+fi
+
+# On systems where [v]snprintf is broken, but is declared in stdio,
+# check that the fmt argument is const char * or just char *.
+# This is only useful for when BROKEN_SNPRINTF
+AC_MSG_CHECKING([whether snprintf can declare const char *fmt])
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#include <stdio.h>
+	   int snprintf(char *a, size_t b, const char *c, ...) { return 0; }
+	   int main(void) { snprintf(0, 0, 0); } 
+    ]])],
+   [AC_MSG_RESULT(yes)
+    AC_DEFINE(SNPRINTF_CONST, [const],
+              [Define as const if snprintf() can declare const char *fmt])],
+   [AC_MSG_RESULT(no)
+    AC_DEFINE(SNPRINTF_CONST, [/* not const */])])
+
 # Check for missing getpeereid (or equiv) support
 NO_PEERCHECK=""
 if test "x$ac_cv_func_getpeereid" != "xyes" ; then
@@ -1326,7 +1425,7 @@ if test "x$ac_cv_func_getpeereid" != "xyes" ; then
 		 #include <sys/socket.h>],
 		[int i = SO_PEERCRED;],
 		[ AC_MSG_RESULT(yes)
-		  AC_DEFINE(HAVE_SO_PEERCRED, [], [Have PEERCRED socket option])
+		  AC_DEFINE(HAVE_SO_PEERCRED, 1, [Have PEERCRED socket option])
 		],
 		[AC_MSG_RESULT(no)
 		NO_PEERCHECK=1]
@@ -1336,21 +1435,21 @@ fi
 dnl see whether mkstemp() requires XXXXXX
 if test "x$ac_cv_func_mkdtemp" = "xyes" ; then
 AC_MSG_CHECKING([for (overly) strict mkstemp])
-AC_TRY_RUN(
-	[
+AC_RUN_IFELSE(
+	[AC_LANG_SOURCE([[
 #include <stdlib.h>
 main() { char template[]="conftest.mkstemp-test";
 if (mkstemp(template) == -1)
 	exit(1);
 unlink(template); exit(0);
 }
-	],
+	]])],
 	[
 		AC_MSG_RESULT(no)
 	],
 	[
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_STRICT_MKSTEMP)
+		AC_DEFINE(HAVE_STRICT_MKSTEMP, 1, [Silly mkstemp()])
 	],
 	[
 		AC_MSG_RESULT(yes)
@@ -1362,8 +1461,8 @@ fi
 dnl make sure that openpty does not reacquire controlling terminal
 if test ! -z "$check_for_openpty_ctty_bug"; then
 	AC_MSG_CHECKING(if openpty correctly handles controlling tty)
-	AC_TRY_RUN(
-		[
+	AC_RUN_IFELSE(
+		[AC_LANG_SOURCE([[
 #include <stdio.h>
 #include <sys/fcntl.h>
 #include <sys/types.h>
@@ -1395,13 +1494,16 @@ main()
 			exit(0);	/* Did not acquire ctty: OK */
 	}
 }
-		],
+		]])],
 		[
 			AC_MSG_RESULT(yes)
 		],
 		[
 			AC_MSG_RESULT(no)
 			AC_DEFINE(SSHD_ACQUIRES_CTTY)
+		],
+		[
+			AC_MSG_RESULT(cross-compiling, assuming yes)
 		]
 	)
 fi
@@ -1409,8 +1511,8 @@ fi
 if test "x$ac_cv_func_getaddrinfo" = "xyes" && \
     test "x$check_for_hpux_broken_getaddrinfo" = "x1"; then
 	AC_MSG_CHECKING(if getaddrinfo seems to work)
-	AC_TRY_RUN(
-		[
+	AC_RUN_IFELSE(
+		[AC_LANG_SOURCE([[
 #include <stdio.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -1464,13 +1566,16 @@ main(void)
 	}
 	exit(0);
 }
-		],
+		]])],
 		[
 			AC_MSG_RESULT(yes)
 		],
 		[
 			AC_MSG_RESULT(no)
 			AC_DEFINE(BROKEN_GETADDRINFO)
+		],
+		[
+			AC_MSG_RESULT(cross-compiling, assuming yes)
 		]
 	)
 fi
@@ -1478,8 +1583,8 @@ fi
 if test "x$ac_cv_func_getaddrinfo" = "xyes" && \
     test "x$check_for_aix_broken_getaddrinfo" = "x1"; then
 	AC_MSG_CHECKING(if getaddrinfo seems to work)
-	AC_TRY_RUN(
-		[
+	AC_RUN_IFELSE(
+		[AC_LANG_SOURCE([[
 #include <stdio.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -1521,15 +1626,18 @@ main(void)
 	}
 	exit(0);
 }
-		],
+		]])],
 		[
 			AC_MSG_RESULT(yes)
-			AC_DEFINE(AIX_GETNAMEINFO_HACK, [],
-[Define if you have a getaddrinfo that fails for the all-zeros IPv6 address])
+			AC_DEFINE(AIX_GETNAMEINFO_HACK, 1,
+				[Define if you have a getaddrinfo that fails
+				for the all-zeros IPv6 address])
 		],
 		[
 			AC_MSG_RESULT(no)
 			AC_DEFINE(BROKEN_GETADDRINFO)
+		],
+			AC_MSG_RESULT(cross-compiling, assuming no)
 		]
 	)
 fi
@@ -1572,7 +1680,8 @@ AC_ARG_WITH(pam,
 
 			PAM_MSG="yes"
 
-			AC_DEFINE(USE_PAM)
+			AC_DEFINE(USE_PAM, 1,
+				[Define if you want to enable PAM support])
 			if test $ac_cv_lib_dl_dlopen = yes; then
 				LIBPAM="-lpam -ldl"
 			else
@@ -1599,7 +1708,9 @@ if test "x$PAM_MSG" = "xyes" ; then
 		[(void)pam_strerror((pam_handle_t *)NULL, -1);],
 		[AC_MSG_RESULT(no)],
 		[
-			AC_DEFINE(HAVE_OLD_PAM)
+			AC_DEFINE(HAVE_OLD_PAM, 1,
+				[Define if you have an old version of PAM
+				which takes only one argument to pam_strerror])
 			AC_MSG_RESULT(yes)
 			PAM_MSG="yes (old library)"
 		]
@@ -1639,7 +1750,9 @@ AC_ARG_WITH(ssl-dir,
 	]
 )
 LIBS="-lcrypto $LIBS"
-AC_TRY_LINK_FUNC(RAND_add, AC_DEFINE(HAVE_OPENSSL),
+AC_TRY_LINK_FUNC(RAND_add, AC_DEFINE(HAVE_OPENSSL, 1,
+	[Define if your ssl headers are included
+	with #include <openssl/header.h>]),
 	[
 		dnl Check default openssl install dir
 		if test -n "${need_dash_r}"; then
@@ -1749,6 +1862,24 @@ Also see contrib/findssl.sh for help identifying header/library mismatches.])
 	]
 )
 
+# Check for OpenSSL without EVP_aes_{192,256}_cbc
+AC_MSG_CHECKING([whether OpenSSL has crippled AES support])
+AC_COMPILE_IFELSE(
+	[AC_LANG_SOURCE([[
+#include <string.h>
+#include <openssl/evp.h>
+int main(void) { exit(EVP_aes_192_cbc() == NULL || EVP_aes_256_cbc() == NULL)}
+	]])],
+	[
+		AC_MSG_RESULT(no)
+	],
+	[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(OPENSSL_LOBOTOMISED_AES, 1,
+		    [libcrypto is missing AES 192 and 256 bit functions])
+	]
+)
+
 # Some systems want crypt() from libcrypt, *not* the version in OpenSSL,
 # because the system crypt() is more featureful.
 if test "x$check_for_libcrypt_before" = "x1"; then
@@ -1813,7 +1944,8 @@ AC_ARG_WITH(rand-helper,
 # Which randomness source do we use?
 if test ! -z "$OPENSSL_SEEDS_ITSELF" && test -z "$USE_RAND_HELPER" ; then
 	# OpenSSL only
-	AC_DEFINE(OPENSSL_PRNG_ONLY)
+	AC_DEFINE(OPENSSL_PRNG_ONLY, 1,
+		[Define if you want OpenSSL's internally seeded PRNG only])
 	RAND_MSG="OpenSSL internal ONLY"
 	INSTALL_SSH_RAND_HELPER=""
 elif test ! -z "$USE_RAND_HELPER" ; then
@@ -1841,7 +1973,8 @@ AC_ARG_WITH(prngd-port,
 		esac
 		if test ! -z "$withval" ; then
 			PRNGD_PORT="$withval"
-			AC_DEFINE_UNQUOTED(PRNGD_PORT, $PRNGD_PORT)
+			AC_DEFINE_UNQUOTED(PRNGD_PORT, $PRNGD_PORT,
+				[Port number of PRNGD/EGD random number socket])
 		fi
 	]
 )
@@ -1872,7 +2005,8 @@ AC_ARG_WITH(prngd-socket,
 				AC_MSG_WARN(Entropy socket is not readable)
 			fi
 			PRNGD_SOCKET="$withval"
-			AC_DEFINE_UNQUOTED(PRNGD_SOCKET, "$PRNGD_SOCKET")
+			AC_DEFINE_UNQUOTED(PRNGD_SOCKET, "$PRNGD_SOCKET",
+				[Location of PRNGD/EGD random number socket])
 		fi
 	],
 	[
@@ -1907,7 +2041,8 @@ AC_ARG_WITH(entropy-timeout,
 		fi
 	]
 )
-AC_DEFINE_UNQUOTED(ENTROPY_TIMEOUT_MSEC, $entropy_timeout)
+AC_DEFINE_UNQUOTED(ENTROPY_TIMEOUT_MSEC, $entropy_timeout,
+	[Builtin PRNG command timeout])
 
 SSH_PRIVSEP_USER=sshd
 AC_ARG_WITH(privsep-user,
@@ -1919,7 +2054,8 @@ AC_ARG_WITH(privsep-user,
 		fi
 	]
 )
-AC_DEFINE_UNQUOTED(SSH_PRIVSEP_USER, "$SSH_PRIVSEP_USER")
+AC_DEFINE_UNQUOTED(SSH_PRIVSEP_USER, "$SSH_PRIVSEP_USER",
+	[non-privileged user for privilege separation])
 AC_SUBST(SSH_PRIVSEP_USER)
 
 # We do this little dance with the search path to insure
@@ -1977,7 +2113,10 @@ if test ! -z "$SONY" ; then
   LIBS="$LIBS -liberty";
 fi
 
-# Checks for data types
+# Check for  long long datatypes
+AC_CHECK_TYPES([long long, unsigned long long, long double])
+
+# Check datatype sizes
 AC_CHECK_SIZEOF(char, 1)
 AC_CHECK_SIZEOF(short int, 2)
 AC_CHECK_SIZEOF(int, 4)
@@ -1989,6 +2128,84 @@ if test "x$ac_cv_sizeof_long_long_int" = "x4" ; then
 	ac_cv_sizeof_long_long_int=0
 fi
 
+# compute LLONG_MIN and LLONG_MAX if we don't know them.
+if test -z "$have_llong_max"; then
+	AC_MSG_CHECKING([for max value of long long])
+	AC_RUN_IFELSE(
+		[AC_LANG_SOURCE([[
+#include <stdio.h>
+/* Why is this so damn hard? */
+#ifdef __GNUC__
+# undef __GNUC__
+#endif
+#define __USE_ISOC99
+#include <limits.h>
+#define DATA "conftest.llminmax"
+int main(void) {
+	FILE *f;
+	long long i, llmin, llmax = 0;
+
+	if((f = fopen(DATA,"w")) == NULL)
+		exit(1);
+
+#if defined(LLONG_MIN) && defined(LLONG_MAX)
+	fprintf(stderr, "Using system header for LLONG_MIN and LLONG_MAX\n");
+	llmin = LLONG_MIN;
+	llmax = LLONG_MAX;
+#else
+	fprintf(stderr, "Calculating  LLONG_MIN and LLONG_MAX\n");
+	/* This will work on one's complement and two's complement */
+	for (i = 1; i > llmax; i <<= 1, i++)
+		llmax = i;
+	llmin = llmax + 1LL;	/* wrap */
+#endif
+
+	/* Sanity check */
+	if (llmin + 1 < llmin || llmin - 1 < llmin || llmax + 1 > llmax
+	    || llmax - 1 > llmax) {
+		fprintf(f, "unknown unknown\n");
+		exit(2);
+	}
+
+	if (fprintf(f ,"%lld %lld", llmin, llmax) < 0)
+		exit(3);
+
+	exit(0);
+}
+		]])],
+		[
+			llong_min=`$AWK '{print $1}' conftest.llminmax`
+			llong_max=`$AWK '{print $2}' conftest.llminmax`
+
+			# snprintf on some Tru64s doesn't understand "%lld"
+			case "$host" in
+			alpha-dec-osf*)
+				if test "x$ac_cv_sizeof_long_long_int" = "x8" &&
+				  test "x$llong_max" = "xld"; then
+					llong_min="-9223372036854775808"
+					llong_max="9223372036854775807"
+				fi
+				;;
+			esac
+
+			AC_MSG_RESULT($llong_max)
+			AC_DEFINE_UNQUOTED(LLONG_MAX, [${llong_max}LL],
+			    [max value of long long calculated by configure])
+			AC_MSG_CHECKING([for min value of long long])
+			AC_MSG_RESULT($llong_min)
+			AC_DEFINE_UNQUOTED(LLONG_MIN, [${llong_min}LL],
+			    [min value of long long calculated by configure])
+		],
+		[
+			AC_MSG_RESULT(not found)
+		],
+		[
+			AC_MSG_WARN([cross compiling: not checking])
+		]
+	)
+fi
+
+
 # More checks for data types
 AC_CACHE_CHECK([for u_int type], ac_cv_have_u_int, [
 	AC_TRY_COMPILE(
@@ -1999,7 +2216,7 @@ AC_CACHE_CHECK([for u_int type], ac_cv_have_u_int, [
 	)
 ])
 if test "x$ac_cv_have_u_int" = "xyes" ; then
-	AC_DEFINE(HAVE_U_INT)
+	AC_DEFINE(HAVE_U_INT, 1, [define if you have u_int data type])
 	have_u_int=1
 fi
 
@@ -2012,7 +2229,7 @@ AC_CACHE_CHECK([for intXX_t types], ac_cv_have_intxx_t, [
 	)
 ])
 if test "x$ac_cv_have_intxx_t" = "xyes" ; then
-	AC_DEFINE(HAVE_INTXX_T)
+	AC_DEFINE(HAVE_INTXX_T, 1, [define if you have intxx_t data type])
 	have_intxx_t=1
 fi
 
@@ -2049,7 +2266,7 @@ AC_CACHE_CHECK([for int64_t type], ac_cv_have_int64_t, [
 	)
 ])
 if test "x$ac_cv_have_int64_t" = "xyes" ; then
-	AC_DEFINE(HAVE_INT64_T)
+	AC_DEFINE(HAVE_INT64_T, 1, [define if you have int64_t data type])
 fi
 
 AC_CACHE_CHECK([for u_intXX_t types], ac_cv_have_u_intxx_t, [
@@ -2061,7 +2278,7 @@ AC_CACHE_CHECK([for u_intXX_t types], ac_cv_have_u_intxx_t, [
 	)
 ])
 if test "x$ac_cv_have_u_intxx_t" = "xyes" ; then
-	AC_DEFINE(HAVE_U_INTXX_T)
+	AC_DEFINE(HAVE_U_INTXX_T, 1, [define if you have u_intxx_t data type])
 	have_u_intxx_t=1
 fi
 
@@ -2087,7 +2304,7 @@ AC_CACHE_CHECK([for u_int64_t types], ac_cv_have_u_int64_t, [
 	)
 ])
 if test "x$ac_cv_have_u_int64_t" = "xyes" ; then
-	AC_DEFINE(HAVE_U_INT64_T)
+	AC_DEFINE(HAVE_U_INT64_T, 1, [define if you have u_int64_t data type])
 	have_u_int64_t=1
 fi
 
@@ -2116,7 +2333,8 @@ if test -z "$have_u_intxx_t" ; then
 		)
 	])
 	if test "x$ac_cv_have_uintxx_t" = "xyes" ; then
-		AC_DEFINE(HAVE_UINTXX_T)
+		AC_DEFINE(HAVE_UINTXX_T, 1,
+			[define if you have uintxx_t data type])
 	fi
 fi
 
@@ -2167,7 +2385,7 @@ AC_CACHE_CHECK([for u_char], ac_cv_have_u_char, [
 	)
 ])
 if test "x$ac_cv_have_u_char" = "xyes" ; then
-	AC_DEFINE(HAVE_U_CHAR)
+	AC_DEFINE(HAVE_U_CHAR, 1, [define if you have u_char data type])
 fi
 
 TYPE_SOCKLEN_T
@@ -2189,7 +2407,7 @@ AC_CACHE_CHECK([for size_t], ac_cv_have_size_t, [
 	)
 ])
 if test "x$ac_cv_have_size_t" = "xyes" ; then
-	AC_DEFINE(HAVE_SIZE_T)
+	AC_DEFINE(HAVE_SIZE_T, 1, [define if you have size_t data type])
 fi
 
 AC_CACHE_CHECK([for ssize_t], ac_cv_have_ssize_t, [
@@ -2203,7 +2421,7 @@ AC_CACHE_CHECK([for ssize_t], ac_cv_have_ssize_t, [
 	)
 ])
 if test "x$ac_cv_have_ssize_t" = "xyes" ; then
-	AC_DEFINE(HAVE_SSIZE_T)
+	AC_DEFINE(HAVE_SSIZE_T, 1, [define if you have ssize_t data type])
 fi
 
 AC_CACHE_CHECK([for clock_t], ac_cv_have_clock_t, [
@@ -2217,7 +2435,7 @@ AC_CACHE_CHECK([for clock_t], ac_cv_have_clock_t, [
 	)
 ])
 if test "x$ac_cv_have_clock_t" = "xyes" ; then
-	AC_DEFINE(HAVE_CLOCK_T)
+	AC_DEFINE(HAVE_CLOCK_T, 1, [define if you have clock_t data type])
 fi
 
 AC_CACHE_CHECK([for sa_family_t], ac_cv_have_sa_family_t, [
@@ -2242,7 +2460,8 @@ AC_CACHE_CHECK([for sa_family_t], ac_cv_have_sa_family_t, [
 	)
 ])
 if test "x$ac_cv_have_sa_family_t" = "xyes" ; then
-	AC_DEFINE(HAVE_SA_FAMILY_T)
+	AC_DEFINE(HAVE_SA_FAMILY_T, 1,
+		[define if you have sa_family_t data type])
 fi
 
 AC_CACHE_CHECK([for pid_t], ac_cv_have_pid_t, [
@@ -2256,7 +2475,7 @@ AC_CACHE_CHECK([for pid_t], ac_cv_have_pid_t, [
 	)
 ])
 if test "x$ac_cv_have_pid_t" = "xyes" ; then
-	AC_DEFINE(HAVE_PID_T)
+	AC_DEFINE(HAVE_PID_T, 1, [define if you have pid_t data type])
 fi
 
 AC_CACHE_CHECK([for mode_t], ac_cv_have_mode_t, [
@@ -2270,7 +2489,7 @@ AC_CACHE_CHECK([for mode_t], ac_cv_have_mode_t, [
 	)
 ])
 if test "x$ac_cv_have_mode_t" = "xyes" ; then
-	AC_DEFINE(HAVE_MODE_T)
+	AC_DEFINE(HAVE_MODE_T, 1, [define if you have mode_t data type])
 fi
 
 
@@ -2286,7 +2505,8 @@ AC_CACHE_CHECK([for struct sockaddr_storage], ac_cv_have_struct_sockaddr_storage
 	)
 ])
 if test "x$ac_cv_have_struct_sockaddr_storage" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_SOCKADDR_STORAGE)
+	AC_DEFINE(HAVE_STRUCT_SOCKADDR_STORAGE, 1,
+		[define if you have struct sockaddr_storage data type])
 fi
 
 AC_CACHE_CHECK([for struct sockaddr_in6], ac_cv_have_struct_sockaddr_in6, [
@@ -2301,7 +2521,8 @@ AC_CACHE_CHECK([for struct sockaddr_in6], ac_cv_have_struct_sockaddr_in6, [
 	)
 ])
 if test "x$ac_cv_have_struct_sockaddr_in6" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6)
+	AC_DEFINE(HAVE_STRUCT_SOCKADDR_IN6, 1,
+		[define if you have struct sockaddr_in6 data type])
 fi
 
 AC_CACHE_CHECK([for struct in6_addr], ac_cv_have_struct_in6_addr, [
@@ -2316,7 +2537,8 @@ AC_CACHE_CHECK([for struct in6_addr], ac_cv_have_struct_in6_addr, [
 	)
 ])
 if test "x$ac_cv_have_struct_in6_addr" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_IN6_ADDR)
+	AC_DEFINE(HAVE_STRUCT_IN6_ADDR, 1,
+		[define if you have struct in6_addr data type])
 fi
 
 AC_CACHE_CHECK([for struct addrinfo], ac_cv_have_struct_addrinfo, [
@@ -2332,7 +2554,8 @@ AC_CACHE_CHECK([for struct addrinfo], ac_cv_have_struct_addrinfo, [
 	)
 ])
 if test "x$ac_cv_have_struct_addrinfo" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_ADDRINFO)
+	AC_DEFINE(HAVE_STRUCT_ADDRINFO, 1,
+		[define if you have struct addrinfo data type])
 fi
 
 AC_CACHE_CHECK([for struct timeval], ac_cv_have_struct_timeval, [
@@ -2344,7 +2567,7 @@ AC_CACHE_CHECK([for struct timeval], ac_cv_have_struct_timeval, [
 	)
 ])
 if test "x$ac_cv_have_struct_timeval" = "xyes" ; then
-	AC_DEFINE(HAVE_STRUCT_TIMEVAL)
+	AC_DEFINE(HAVE_STRUCT_TIMEVAL, 1, [define if you have struct timeval])
 	have_struct_timeval=1
 fi
 
@@ -2409,6 +2632,17 @@ OSSH_CHECK_HEADER_FOR_FIELD(ut_time, utmpx.h, HAVE_TIME_IN_UTMPX)
 OSSH_CHECK_HEADER_FOR_FIELD(ut_tv, utmpx.h, HAVE_TV_IN_UTMPX)
 
 AC_CHECK_MEMBERS([struct stat.st_blksize])
+AC_CHECK_MEMBER([struct __res_state.retrans], [], [AC_DEFINE(__res_state, state,
+	[Define if we don't have struct __res_state in resolv.h])],
+[
+#include <stdio.h>
+#if HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+])
 
 AC_CACHE_CHECK([for ss_family field in struct sockaddr_storage],
 		ac_cv_have_ss_family_in_struct_ss, [
@@ -2423,7 +2657,7 @@ AC_CACHE_CHECK([for ss_family field in struct sockaddr_storage],
 	)
 ])
 if test "x$ac_cv_have_ss_family_in_struct_ss" = "xyes" ; then
-	AC_DEFINE(HAVE_SS_FAMILY_IN_SS)
+	AC_DEFINE(HAVE_SS_FAMILY_IN_SS, 1, [Fields in struct sockaddr_storage])
 fi
 
 AC_CACHE_CHECK([for __ss_family field in struct sockaddr_storage],
@@ -2439,7 +2673,8 @@ AC_CACHE_CHECK([for __ss_family field in struct sockaddr_storage],
 	)
 ])
 if test "x$ac_cv_have___ss_family_in_struct_ss" = "xyes" ; then
-	AC_DEFINE(HAVE___SS_FAMILY_IN_SS)
+	AC_DEFINE(HAVE___SS_FAMILY_IN_SS, 1,
+		[Fields in struct sockaddr_storage])
 fi
 
 AC_CACHE_CHECK([for pw_class field in struct passwd],
@@ -2454,7 +2689,8 @@ AC_CACHE_CHECK([for pw_class field in struct passwd],
 	)
 ])
 if test "x$ac_cv_have_pw_class_in_struct_passwd" = "xyes" ; then
-	AC_DEFINE(HAVE_PW_CLASS_IN_PASSWD)
+	AC_DEFINE(HAVE_PW_CLASS_IN_PASSWD, 1,
+		[Define if your password has a pw_class field])
 fi
 
 AC_CACHE_CHECK([for pw_expire field in struct passwd],
@@ -2469,7 +2705,8 @@ AC_CACHE_CHECK([for pw_expire field in struct passwd],
 	)
 ])
 if test "x$ac_cv_have_pw_expire_in_struct_passwd" = "xyes" ; then
-	AC_DEFINE(HAVE_PW_EXPIRE_IN_PASSWD)
+	AC_DEFINE(HAVE_PW_EXPIRE_IN_PASSWD, 1,
+		[Define if your password has a pw_expire field])
 fi
 
 AC_CACHE_CHECK([for pw_change field in struct passwd],
@@ -2484,7 +2721,8 @@ AC_CACHE_CHECK([for pw_change field in struct passwd],
 	)
 ])
 if test "x$ac_cv_have_pw_change_in_struct_passwd" = "xyes" ; then
-	AC_DEFINE(HAVE_PW_CHANGE_IN_PASSWD)
+	AC_DEFINE(HAVE_PW_CHANGE_IN_PASSWD, 1,
+		[Define if your password has a pw_change field])
 fi
 
 dnl make sure we're using the real structure members and not defines
@@ -2510,7 +2748,9 @@ exit(0);
 	)
 ])
 if test "x$ac_cv_have_accrights_in_msghdr" = "xyes" ; then
-	AC_DEFINE(HAVE_ACCRIGHTS_IN_MSGHDR)
+	AC_DEFINE(HAVE_ACCRIGHTS_IN_MSGHDR, 1,
+		[Define if your system uses access rights style
+		file descriptor passing])
 fi
 
 AC_CACHE_CHECK([for msg_control field in struct msghdr],
@@ -2535,7 +2775,9 @@ exit(0);
 	)
 ])
 if test "x$ac_cv_have_control_in_msghdr" = "xyes" ; then
-	AC_DEFINE(HAVE_CONTROL_IN_MSGHDR)
+	AC_DEFINE(HAVE_CONTROL_IN_MSGHDR, 1,
+		[Define if your system uses ancillary data style
+		file descriptor passing])
 fi
 
 AC_CACHE_CHECK([if libc defines __progname], ac_cv_libc_defines___progname, [
@@ -2546,7 +2788,7 @@ AC_CACHE_CHECK([if libc defines __progname], ac_cv_libc_defines___progname, [
 	)
 ])
 if test "x$ac_cv_libc_defines___progname" = "xyes" ; then
-	AC_DEFINE(HAVE___PROGNAME)
+	AC_DEFINE(HAVE___PROGNAME, 1, [Define if libc defines __progname])
 fi
 
 AC_CACHE_CHECK([whether $CC implements __FUNCTION__], ac_cv_cc_implements___FUNCTION__, [
@@ -2559,7 +2801,8 @@ AC_CACHE_CHECK([whether $CC implements __FUNCTION__], ac_cv_cc_implements___FUNC
 	)
 ])
 if test "x$ac_cv_cc_implements___FUNCTION__" = "xyes" ; then
-	AC_DEFINE(HAVE___FUNCTION__)
+	AC_DEFINE(HAVE___FUNCTION__, 1,
+		[Define if compiler implements __FUNCTION__])
 fi
 
 AC_CACHE_CHECK([whether $CC implements __func__], ac_cv_cc_implements___func__, [
@@ -2572,7 +2815,33 @@ AC_CACHE_CHECK([whether $CC implements __func__], ac_cv_cc_implements___func__,
 	)
 ])
 if test "x$ac_cv_cc_implements___func__" = "xyes" ; then
-	AC_DEFINE(HAVE___func__)
+	AC_DEFINE(HAVE___func__, 1, [Define if compiler implements __func__])
+fi
+
+AC_CACHE_CHECK([whether va_copy exists], ac_cv_have_va_copy, [
+	AC_TRY_LINK(
+		[#include <stdarg.h>
+		 va_list x,y;],
+	    	[va_copy(x,y);],
+		[ ac_cv_have_va_copy="yes" ],
+		[ ac_cv_have_va_copy="no" ]
+	)
+])
+if test "x$ac_cv_have_va_copy" = "xyes" ; then
+	AC_DEFINE(HAVE_VA_COPY, 1, [Define if va_copy exists])
+fi
+
+AC_CACHE_CHECK([whether __va_copy exists], ac_cv_have___va_copy, [
+	AC_TRY_LINK(
+		[#include <stdarg.h>
+		 va_list x,y;],
+	    	[__va_copy(x,y);],
+		[ ac_cv_have___va_copy="yes" ],
+		[ ac_cv_have___va_copy="no" ]
+	)
+])
+if test "x$ac_cv_have___va_copy" = "xyes" ; then
+	AC_DEFINE(HAVE___VA_COPY, 1, [Define if __va_copy exists])
 fi
 
 AC_CACHE_CHECK([whether getopt has optreset support],
@@ -2591,7 +2860,8 @@ AC_CACHE_CHECK([whether getopt has optreset support],
 	)
 ])
 if test "x$ac_cv_have_getopt_optreset" = "xyes" ; then
-	AC_DEFINE(HAVE_GETOPT_OPTRESET)
+	AC_DEFINE(HAVE_GETOPT_OPTRESET, 1,
+		[Define if your getopt(3) defines and uses optreset])
 fi
 
 AC_CACHE_CHECK([if libc defines sys_errlist], ac_cv_libc_defines_sys_errlist, [
@@ -2602,7 +2872,8 @@ AC_CACHE_CHECK([if libc defines sys_errlist], ac_cv_libc_defines_sys_errlist, [
 	)
 ])
 if test "x$ac_cv_libc_defines_sys_errlist" = "xyes" ; then
-	AC_DEFINE(HAVE_SYS_ERRLIST)
+	AC_DEFINE(HAVE_SYS_ERRLIST, 1,
+		[Define if your system defines sys_errlist[]])
 fi
 
 
@@ -2614,7 +2885,7 @@ AC_CACHE_CHECK([if libc defines sys_nerr], ac_cv_libc_defines_sys_nerr, [
 	)
 ])
 if test "x$ac_cv_libc_defines_sys_nerr" = "xyes" ; then
-	AC_DEFINE(HAVE_SYS_NERR)
+	AC_DEFINE(HAVE_SYS_NERR, 1, [Define if your system defines sys_nerr])
 fi
 
 SCARD_MSG="no"
@@ -2641,8 +2912,11 @@ AC_ARG_WITH(sectok,
 			if test "$ac_cv_lib_sectok_sectok_open" != yes; then
 				AC_MSG_ERROR(Can't find libsectok)
 			fi
-			AC_DEFINE(SMARTCARD)
-			AC_DEFINE(USE_SECTOK)
+			AC_DEFINE(SMARTCARD, 1,
+				[Define if you want smartcard support])
+			AC_DEFINE(USE_SECTOK, 1,
+				[Define if you want smartcard support
+				using sectok])
 			SCARD_MSG="yes, using sectok"
 		fi
 	]
@@ -2651,7 +2925,7 @@ AC_ARG_WITH(sectok,
 # Check whether user wants OpenSC support
 OPENSC_CONFIG="no"
 AC_ARG_WITH(opensc,
-	[--with-opensc[[=PFX]]       Enable smartcard support using OpenSC (optionally in PATH)],
+	[  --with-opensc[[=PFX]]     Enable smartcard support using OpenSC (optionally in PATH)],
 	[
 	    if test "x$withval" != "xno" ; then
 		if test "x$withval" != "xyes" ; then
@@ -2665,7 +2939,9 @@ AC_ARG_WITH(opensc,
 			CPPFLAGS="$CPPFLAGS $LIBOPENSC_CFLAGS"
 			LDFLAGS="$LDFLAGS $LIBOPENSC_LIBS"
 			AC_DEFINE(SMARTCARD)
-			AC_DEFINE(USE_OPENSC)
+			AC_DEFINE(USE_OPENSC, 1,
+				[Define if you want smartcard support
+				using OpenSC])
 			SCARD_MSG="yes, using OpenSC"
 		fi
 	    fi
@@ -2674,7 +2950,8 @@ AC_ARG_WITH(opensc,
 
 # Check libraries needed by DNS fingerprint support
 AC_SEARCH_LIBS(getrrsetbyname, resolv,
-	[AC_DEFINE(HAVE_GETRRSETBYNAME)],
+	[AC_DEFINE(HAVE_GETRRSETBYNAME, 1,
+		[Define if getrrsetbyname() exists])],
 	[
 		# Needed by our getrrsetbyname()
 		AC_SEARCH_LIBS(res_query, resolv)
@@ -2703,7 +2980,8 @@ int main()
 		    [#include <sys/types.h>
 		    #include <arpa/nameser.h>])
 		AC_CHECK_MEMBER(HEADER.ad,
-			[AC_DEFINE(HAVE_HEADER_AD)],,
+			[AC_DEFINE(HAVE_HEADER_AD, 1,
+			    [Define if HEADER.ad exists in arpa/nameser.h])],,
 			[#include <arpa/nameser.h>])
 	])
 
@@ -2718,7 +2996,7 @@ AC_ARG_WITH(kerberos5,
 			KRB5ROOT=${withval}
 		fi
 
-		AC_DEFINE(KRB5)
+		AC_DEFINE(KRB5, 1, [Define if you want Kerberos 5 support])
 		KRB5_MSG="yes"
 
 		AC_MSG_CHECKING(for krb5-config)
@@ -2729,7 +3007,9 @@ AC_ARG_WITH(kerberos5,
 			AC_MSG_CHECKING(for gssapi support)
 			if $KRB5CONF | grep gssapi >/dev/null ; then
 				AC_MSG_RESULT(yes)
-				AC_DEFINE(GSSAPI)
+				AC_DEFINE(GSSAPI, 1,
+					[Define this if you want GSSAPI
+					support in the version 2 protocol])
 				k5confopts=gssapi
 			else
 				AC_MSG_RESULT(no)
@@ -2742,7 +3022,9 @@ AC_ARG_WITH(kerberos5,
 			AC_TRY_COMPILE([ #include <krb5.h> ],
 				       [ char *tmp = heimdal_version; ],
 				       [ AC_MSG_RESULT(yes)
-					 AC_DEFINE(HEIMDAL) ],
+					 AC_DEFINE(HEIMDAL, 1,
+					[Define this if you are using the
+					Heimdal version of Kerberos V5]) ],
 				         AC_MSG_RESULT(no)
 			)
 		else
@@ -2797,14 +3079,15 @@ AC_ARG_WITH(kerberos5,
 		if test ! -z "$blibpath" ; then
 			blibpath="$blibpath:${KRB5ROOT}/lib"
 		fi
-	fi
 
-	AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h)
-	AC_CHECK_HEADERS(gssapi_krb5.h gssapi/gssapi_krb5.h)
-	AC_CHECK_HEADERS(gssapi_generic.h gssapi/gssapi_generic.h)
+		AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h)
+		AC_CHECK_HEADERS(gssapi_krb5.h gssapi/gssapi_krb5.h)
+		AC_CHECK_HEADERS(gssapi_generic.h gssapi/gssapi_generic.h)
 
-	LIBS="$LIBS $K5LIBS"
-	AC_SEARCH_LIBS(k_hasafs, kafs, AC_DEFINE(USE_AFS))
+		LIBS="$LIBS $K5LIBS"
+		AC_SEARCH_LIBS(k_hasafs, kafs, AC_DEFINE(USE_AFS, 1,
+			[Define this if you want to use libkafs' AFS support]))
+	fi
 	]
 )
 
@@ -2858,7 +3141,8 @@ if test -z "$xauth_path" ; then
 	XAUTH_PATH="undefined"
 	AC_SUBST(XAUTH_PATH)
 else
-	AC_DEFINE_UNQUOTED(XAUTH_PATH, "$xauth_path")
+	AC_DEFINE_UNQUOTED(XAUTH_PATH, "$xauth_path",
+		[Define if xauth is found in your path])
 	XAUTH_PATH=$xauth_path
 	AC_SUBST(XAUTH_PATH)
 fi
@@ -2866,7 +3150,8 @@ fi
 # Check for mail directory (last resort if we cannot get it from headers)
 if test ! -z "$MAIL" ; then
 	maildir=`dirname $MAIL`
-	AC_DEFINE_UNQUOTED(MAIL_DIRECTORY, "$maildir")
+	AC_DEFINE_UNQUOTED(MAIL_DIRECTORY, "$maildir",
+		[Set this to your mail directory if you don't have maillock.h])
 fi
 
 if test ! -z "$cross_compiling" && test "x$cross_compiling" = "xyes"; then
@@ -2877,7 +3162,8 @@ if test -z "$no_dev_ptmx" ; then
 	if test "x$disable_ptmx_check" != "xyes" ; then
 		AC_CHECK_FILE("/dev/ptmx",
 			[
-				AC_DEFINE_UNQUOTED(HAVE_DEV_PTMX)
+				AC_DEFINE_UNQUOTED(HAVE_DEV_PTMX, 1,
+					[Define if you have /dev/ptmx])
 				have_dev_ptmx=1
 			]
 		)
@@ -2887,7 +3173,8 @@ fi
 if test ! -z "$cross_compiling" && test "x$cross_compiling" != "xyes"; then
 	AC_CHECK_FILE("/dev/ptc",
 		[
-			AC_DEFINE_UNQUOTED(HAVE_DEV_PTS_AND_PTC)
+			AC_DEFINE_UNQUOTED(HAVE_DEV_PTS_AND_PTC, 1,
+				[Define if you have /dev/ptc])
 			have_dev_ptc=1
 		]
 	)
@@ -2934,7 +3221,8 @@ AC_ARG_WITH(md5-passwords,
 	[  --with-md5-passwords    Enable use of MD5 passwords],
 	[
 		if test "x$withval" != "xno" ; then
-			AC_DEFINE(HAVE_MD5_PASSWORDS)
+			AC_DEFINE(HAVE_MD5_PASSWORDS, 1,
+				[Define if you want to allow MD5 passwords])
 			MD5_MSG="yes"
 		fi
 	]
@@ -2964,7 +3252,8 @@ if test -z "$disable_shadow" ; then
 
 	if test "x$sp_expire_available" = "xyes" ; then
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAS_SHADOW_EXPIRE)
+		AC_DEFINE(HAS_SHADOW_EXPIRE, 1,
+		    [Define if you want to use shadow password expire field])
 	else
 		AC_MSG_RESULT(no)
 	fi
@@ -2973,7 +3262,9 @@ fi
 # Use ip address instead of hostname in $DISPLAY
 if test ! -z "$IPADDR_IN_DISPLAY" ; then
 	DISPLAY_HACK_MSG="yes"
-	AC_DEFINE(IPADDR_IN_DISPLAY)
+	AC_DEFINE(IPADDR_IN_DISPLAY, 1,
+		[Define if you need to use IP address
+		instead of hostname in $DISPLAY])
 else
 	DISPLAY_HACK_MSG="no"
 	AC_ARG_WITH(ipaddr-display,
@@ -2996,17 +3287,21 @@ AC_ARG_ENABLE(etc-default-login,
 	  else
 		etc_default_login=yes
 	  fi ],
-	[ etc_default_login=yes ]
+	[ if test ! -z "$cross_compiling" && test "x$cross_compiling" = "xyes";
+	  then
+		AC_MSG_WARN([cross compiling: not checking /etc/default/login])
+		etc_default_login=no
+	  else
+		etc_default_login=yes
+	  fi ]
 )
 
 if test "x$etc_default_login" != "xno"; then
 	AC_CHECK_FILE("/etc/default/login",
 	    [ external_path_file=/etc/default/login ])
-	if test ! -z "$cross_compiling" && test "x$cross_compiling" = "xyes";
-	then
-		AC_MSG_WARN([cross compiling: Disabling /etc/default/login test])
-	elif test "x$external_path_file" = "x/etc/default/login"; then
-		AC_DEFINE(HAVE_ETC_DEFAULT_LOGIN)
+	if test "x$external_path_file" = "x/etc/default/login"; then
+		AC_DEFINE(HAVE_ETC_DEFAULT_LOGIN, 1,
+			[Define if your system has /etc/default/login])
 	fi
 fi
 
@@ -3043,8 +3338,8 @@ $external_path_file .])
 If PATH is defined in $external_path_file, ensure the path to scp is included,
 otherwise scp will not work.])
 		fi
-		AC_TRY_RUN(
-			[
+		AC_RUN_IFELSE(
+			[AC_LANG_SOURCE([[
 /* find out what STDPATH is */
 #include <stdio.h>
 #ifdef HAVE_PATHS_H
@@ -3076,7 +3371,8 @@ main()
 
 	exit(0);
 }
-		], [ user_path=`cat conftest.stdpath` ],
+		]])],
+		[ user_path=`cat conftest.stdpath` ],
 		[ user_path="/usr/bin:/bin:/usr/sbin:/sbin" ],
 		[ user_path="/usr/bin:/bin:/usr/sbin:/sbin" ]
 	)
@@ -3099,7 +3395,7 @@ main()
 	fi ]
 )
 if test "x$external_path_file" != "x/etc/login.conf" ; then
-	AC_DEFINE_UNQUOTED(USER_PATH, "$user_path")
+	AC_DEFINE_UNQUOTED(USER_PATH, "$user_path", [Specify default $PATH])
 	AC_SUBST(user_path)
 fi
 
@@ -3109,7 +3405,9 @@ AC_ARG_WITH(superuser-path,
 	[
 		if test -n "$withval"  &&  test "x$withval" != "xno"  &&  \
 		    test "x${withval}" != "xyes"; then
-			AC_DEFINE_UNQUOTED(SUPERUSER_PATH, "$withval")
+			AC_DEFINE_UNQUOTED(SUPERUSER_PATH, "$withval",
+				[Define if you want a different $PATH
+				for the superuser])
 			superuser_path=$withval
 		fi
 	]
@@ -3123,7 +3421,9 @@ AC_ARG_WITH(4in6,
 	[
 		if test "x$withval" != "xno" ; then
 			AC_MSG_RESULT(yes)
-			AC_DEFINE(IPV4_IN_IPV6)
+			AC_DEFINE(IPV4_IN_IPV6, 1,
+				[Detect IPv4 in IPv6 mapped addresses
+				and treat as IPv4])
 			IPV4_IN6_HACK_MSG="yes"
 		else
 			AC_MSG_RESULT(no)
@@ -3145,7 +3445,8 @@ AC_ARG_WITH(bsd-auth,
 	[  --with-bsd-auth         Enable BSD auth support],
 	[
 		if test "x$withval" != "xno" ; then
-			AC_DEFINE(BSD_AUTH)
+			AC_DEFINE(BSD_AUTH, 1,
+				[Define if you have BSD auth support])
 			BSD_AUTH_MSG=yes
 		fi
 	]
@@ -3174,7 +3475,7 @@ AC_ARG_WITH(pid-dir,
 	]
 )
 
-AC_DEFINE_UNQUOTED(_PATH_SSH_PIDDIR, "$piddir")
+AC_DEFINE_UNQUOTED(_PATH_SSH_PIDDIR, "$piddir", [Specify location of ssh.pid])
 AC_SUBST(piddir)
 
 dnl allow user to disable some login recording features
@@ -3198,7 +3499,8 @@ AC_ARG_ENABLE(utmpx,
 	[  --disable-utmpx         disable use of utmpx even if detected [no]],
 	[
 		if test "x$enableval" = "xno" ; then
-			AC_DEFINE(DISABLE_UTMPX)
+			AC_DEFINE(DISABLE_UTMPX, 1,
+				[Define if you don't want to use utmpx])
 		fi
 	]
 )
@@ -3214,7 +3516,8 @@ AC_ARG_ENABLE(wtmpx,
 	[  --disable-wtmpx         disable use of wtmpx even if detected [no]],
 	[
 		if test "x$enableval" = "xno" ; then
-			AC_DEFINE(DISABLE_WTMPX)
+			AC_DEFINE(DISABLE_WTMPX, 1,
+				[Define if you don't want to use wtmpx])
 		fi
 	]
 )
@@ -3230,7 +3533,9 @@ AC_ARG_ENABLE(pututline,
 	[  --disable-pututline     disable use of pututline() etc. ([uw]tmp) [no]],
 	[
 		if test "x$enableval" = "xno" ; then
-			AC_DEFINE(DISABLE_PUTUTLINE)
+			AC_DEFINE(DISABLE_PUTUTLINE, 1,
+				[Define if you don't want to use pututline()
+				etc. to write [uw]tmp])
 		fi
 	]
 )
@@ -3238,7 +3543,9 @@ AC_ARG_ENABLE(pututxline,
 	[  --disable-pututxline    disable use of pututxline() etc. ([uw]tmpx) [no]],
 	[
 		if test "x$enableval" = "xno" ; then
-			AC_DEFINE(DISABLE_PUTUTXLINE)
+			AC_DEFINE(DISABLE_PUTUTXLINE, 1,
+				[Define if you don't want to use pututxline()
+				etc. to write [uw]tmpx])
 		fi
 	]
 )
@@ -3313,7 +3620,8 @@ if test -z "$conf_lastlog_location"; then
 fi
 
 if test -n "$conf_lastlog_location"; then
-	AC_DEFINE_UNQUOTED(CONF_LASTLOG_FILE, "$conf_lastlog_location")
+	AC_DEFINE_UNQUOTED(CONF_LASTLOG_FILE, "$conf_lastlog_location",
+		[Define if you want to specify the path to your lastlog file])
 fi
 
 dnl utmp detection
@@ -3343,7 +3651,8 @@ if test -z "$conf_utmp_location"; then
 	fi
 fi
 if test -n "$conf_utmp_location"; then
-	AC_DEFINE_UNQUOTED(CONF_UTMP_FILE, "$conf_utmp_location")
+	AC_DEFINE_UNQUOTED(CONF_UTMP_FILE, "$conf_utmp_location",
+		[Define if you want to specify the path to your utmp file])
 fi
 
 dnl wtmp detection
@@ -3373,7 +3682,8 @@ if test -z "$conf_wtmp_location"; then
 	fi
 fi
 if test -n "$conf_wtmp_location"; then
-	AC_DEFINE_UNQUOTED(CONF_WTMP_FILE, "$conf_wtmp_location")
+	AC_DEFINE_UNQUOTED(CONF_WTMP_FILE, "$conf_wtmp_location",
+		[Define if you want to specify the path to your wtmp file])
 fi
 
 
@@ -3401,7 +3711,8 @@ if test -z "$conf_utmpx_location"; then
 		AC_DEFINE(DISABLE_UTMPX)
 	fi
 else
-	AC_DEFINE_UNQUOTED(CONF_UTMPX_FILE, "$conf_utmpx_location")
+	AC_DEFINE_UNQUOTED(CONF_UTMPX_FILE, "$conf_utmpx_location",
+		[Define if you want to specify the path to your utmpx file])
 fi
 
 dnl wtmpx detection
@@ -3426,7 +3737,8 @@ if test -z "$conf_wtmpx_location"; then
 		AC_DEFINE(DISABLE_WTMPX)
 	fi
 else
-	AC_DEFINE_UNQUOTED(CONF_WTMPX_FILE, "$conf_wtmpx_location")
+	AC_DEFINE_UNQUOTED(CONF_WTMPX_FILE, "$conf_wtmpx_location",
+		[Define if you want to specify the path to your wtmpx file])
 fi