Patch file created at Oracle to use krb5-config to discover libraries

and include paths for linking with gssapi.

Intention is to share patch with ISC for their inclusion in future

releases of BIND.

--- a/configure.in	Thu Jun  2 11:28:43 2016

+++ b/configure.in	Thu Jun  2 11:43:34 2016

@@ -799,6 +799,49 @@

 [  --with-gssapi=PATH      Specify path for system-supplied GSSAPI [[default=yes]]],

     use_gssapi="$withval", use_gssapi="yes")

+# first try using krb5-config, if that does not work then fall back to "yes" method.

+if test "$use_gssapi" = "krb5-config"

+then

+    AC_MSG_RESULT(trying krb5_config)

+    AC_PATH_PROG(KRB5_CONFIG, krb5-config)

+    gssapi_cflags=`$KRB5_CONFIG --cflags gssapi`

+    gssapi_libs=`$KRB5_CONFIG --libs gssapi`

+    saved_cppflags="$CPPFLAGS"

+    CPPFLAGS="$gssapi_cflags $CPPFLAGS"

+    AC_CHECK_HEADERS(gssapi.h gssapi/gssapi.h,

+	[ISC_PLATFORM_GSSAPIHEADER="#define ISC_PLATFORM_GSSAPIHEADER <$ac_header>"])

+    if test "$ISC_PLATFORM_GSSAPIHEADER" = ""; then

+	AC_MSG_RESULT([krb5-config: gssapi.h not found])

+	CPPFLAGS="$saved_cppflags"

+	use_gssapi="yes"

+    else

+	AC_CHECK_HEADERS(krb5/krb5.h krb5.h,

+	    [ISC_PLATFORM_KRB5HEADER="#define ISC_PLATFORM_KRB5HEADER <$ac_header>"])

+	if test "$ISC_PLATFORM_KRB5HEADER" = ""; then

+	    AC_MSG_RESULT([krb5-config: krb5.h not found])

+	    CPPFLAGS="$saved_cppflags"

+	    use_gssapi="yes"

+	else

+	    CPPFLAGS="$saved_cppflags"

+	    saved_libs="$LIBS"

+	    LIBS=$gssapi_libs

+	    AC_MSG_CHECKING([krb5-config linking as $LIBS])

+	    AC_TRY_LINK( , [gss_acquire_cred();krb5_init_context()],

+		gssapi_linked=yes, gssapi_linked=no)

+	    case $gssapi_linked in

+		yes) AC_MSG_RESULT([krb5-config: linked]);;

+		no)  AC_MSG_RESULT([krb5-config: could not determine proper GSSAPI linkage])

+		    use_gssapi="yes"

+		    ;;

+	    esac

+	    LIBS=$saved_libs

+	fi

+    fi

+    if test "$use_gssapi" = "yes"; then

+	AC_MSG_CHECKING([for GSSAPI library, non krb5-config method])

+    fi

+fi

+

 # gssapi is just the framework, we really require kerberos v5, so

 # look for those headers (the gssapi headers must be there, too)

 # The problem with this implementation is that it doesn't allow

@@ -842,6 +885,11 @@

 	yes)

 		AC_MSG_ERROR([--with-gssapi must specify a path])

 		;;

+	krb5-config)

+		USE_GSSAPI='-DGSSAPI'

+		DST_GSSAPI_INC="$gssapi_cflags"

+		DNS_GSSAPI_LIBS="$gssapi_libs"

+		;;

 	*)

 		AC_MSG_RESULT(looking in $use_gssapi/lib)

 		USE_GSSAPI='-DGSSAPI'

--- a/configure	Sun Feb 28 16:29:06 2016

+++ b/configure	Thu Jun  2 03:56:59 2016

@@ -1,5 +1,5 @@

 #! /bin/sh

-# Copyright (C) 2004-2015  Internet Systems Consortium, Inc. ("ISC")

+# Copyright (C) 2004-2016  Internet Systems Consortium, Inc. ("ISC")

 # Copyright (C) 1996-2003  Internet Software Consortium.

 #

 # Permission to use, copy, modify, and/or distribute this software for any

@@ -851,6 +851,7 @@

 ISC_PLATFORM_GSSAPI_KRB5_HEADER

 ISC_PLATFORM_GSSAPIHEADER

 ISC_PLATFORM_HAVEGSSAPI

+KRB5_CONFIG

 GEOIPLINKOBJS

 GEOIPLINKSRCS

 LWRES_PLATFORM_NEEDSYSSELECTH

@@ -13975,6 +13976,133 @@

 fi

+# first try using krb5-config, if that does not work then fall back to "yes" method.

+if test "$use_gssapi" = "krb5-config"

+then

+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: trying krb5_config" >&5

+$as_echo "trying krb5_config" >&6; }

+    # Extract the first word of "krb5-config", so it can be a program name with args.

+set dummy krb5-config; ac_word=$2

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5

+$as_echo_n "checking for $ac_word... " >&6; }

+if ${ac_cv_path_KRB5_CONFIG+:} false; then :

+  $as_echo_n "(cached) " >&6

+else

+  case $KRB5_CONFIG in

+  [\\/]* | ?:[\\/]*)

+  ac_cv_path_KRB5_CONFIG="$KRB5_CONFIG" # Let the user override the test with a path.

+  ;;

+  *)

+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR

+for as_dir in $PATH

+do

+  IFS=$as_save_IFS

+  test -z "$as_dir" && as_dir=.

+    for ac_exec_ext in '' $ac_executable_extensions; do

+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then

+    ac_cv_path_KRB5_CONFIG="$as_dir/$ac_word$ac_exec_ext"

+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5

+    break 2

+  fi

+done

+  done

+IFS=$as_save_IFS

+

+  ;;

+esac

+fi

+KRB5_CONFIG=$ac_cv_path_KRB5_CONFIG

+if test -n "$KRB5_CONFIG"; then

+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $KRB5_CONFIG" >&5

+$as_echo "$KRB5_CONFIG" >&6; }

+else

+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5

+$as_echo "no" >&6; }

+fi

+

+

+    gssapi_cflags=`$KRB5_CONFIG --cflags gssapi`

+    gssapi_libs=`$KRB5_CONFIG --libs gssapi`

+    saved_cppflags="$CPPFLAGS"

+    CPPFLAGS="$gssapi_cflags $CPPFLAGS"

+    for ac_header in gssapi.h gssapi/gssapi.h

+do :

+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`

+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"

+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :

+  cat >>confdefs.h <<_ACEOF

+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1

+_ACEOF

+ ISC_PLATFORM_GSSAPIHEADER="#define ISC_PLATFORM_GSSAPIHEADER <$ac_header>"

+fi

+

+done

+

+    if test "$ISC_PLATFORM_GSSAPIHEADER" = ""; then

+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: krb5-config: gssapi.h not found" >&5

+$as_echo "krb5-config: gssapi.h not found" >&6; }

+	CPPFLAGS="$saved_cppflags"

+	use_gssapi="yes"

+    else

+	for ac_header in krb5/krb5.h krb5.h

+do :

+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`

+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"

+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :

+  cat >>confdefs.h <<_ACEOF

+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1

+_ACEOF

+ ISC_PLATFORM_KRB5HEADER="#define ISC_PLATFORM_KRB5HEADER <$ac_header>"

+fi

+

+done

+

+	if test "$ISC_PLATFORM_KRB5HEADER" = ""; then

+	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: krb5-config: krb5.h not found" >&5

+$as_echo "krb5-config: krb5.h not found" >&6; }

+	    CPPFLAGS="$saved_cppflags"

+	    use_gssapi="yes"

+	else

+	    CPPFLAGS="$saved_cppflags"

+	    saved_libs="$LIBS"

+	    LIBS=$gssapi_libs

+	    { $as_echo "$as_me:${as_lineno-$LINENO}: checking krb5-config linking as $LIBS" >&5

+$as_echo_n "checking krb5-config linking as $LIBS... " >&6; }

+	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext

+/* end confdefs.h.  */

+

+int

+main ()

+{

+gss_acquire_cred();krb5_init_context()

+  ;

+  return 0;

+}

+_ACEOF

+if ac_fn_c_try_link "$LINENO"; then :

+  gssapi_linked=yes

+else

+  gssapi_linked=no

+fi

+rm -f core conftest.err conftest.$ac_objext \

+    conftest$ac_exeext conftest.$ac_ext

+	    case $gssapi_linked in

+		yes) { $as_echo "$as_me:${as_lineno-$LINENO}: result: krb5-config: linked" >&5

+$as_echo "krb5-config: linked" >&6; };;

+		no)  { $as_echo "$as_me:${as_lineno-$LINENO}: result: krb5-config: could not determine proper GSSAPI linkage" >&5

+$as_echo "krb5-config: could not determine proper GSSAPI linkage" >&6; }

+		    use_gssapi="yes"

+		    ;;

+	    esac

+	    LIBS=$saved_libs

+	fi

+    fi

+    if test "$use_gssapi" = "yes"; then

+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for GSSAPI library, non krb5-config method" >&5

+$as_echo_n "checking for GSSAPI library, non krb5-config method... " >&6; }

+    fi

+fi

+

 # gssapi is just the framework, we really require kerberos v5, so

 # look for those headers (the gssapi headers must be there, too)

 # The problem with this implementation is that it doesn't allow

@@ -14019,6 +14147,11 @@

 	yes)

 		as_fn_error $? "--with-gssapi must specify a path" "$LINENO" 5

 		;;

+	krb5-config)

+		USE_GSSAPI='-DGSSAPI'

+		DST_GSSAPI_INC="$gssapi_cflags"

+		DNS_GSSAPI_LIBS="$gssapi_libs"

+		;;

 	*)

 		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: looking in $use_gssapi/lib" >&5

 $as_echo "looking in $use_gssapi/lib" >&6; }