cleanup matelib and mate examples
[obnox/wireshark/wip.git] / acinclude.m4
index 6e948fb2c6d79ae63b9e362f379f8df9f1dd8183..6b089c4ea42e8334de1357dfad1da4fdfd3f71d2 100644 (file)
@@ -2,7 +2,7 @@ dnl Macros that test for specific features.
 dnl This file is part of the Autoconf packaging for Ethereal.
 dnl Copyright (C) 1998-2000 by Gerald Combs.
 dnl
-dnl $Id: acinclude.m4,v 1.53 2003/02/28 06:04:30 guy Exp $
+dnl $Id$
 dnl
 dnl This program is free software; you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -60,7 +60,7 @@ dnl Roland McGrath, Noah Friedman, david d zuhn, and many others.
 # XXX - IRIX, and other OSes, may require some flag equivalent to
 # "-R" here.
 #
-AC_DEFUN(AC_ETHEREAL_ADD_DASH_L,
+AC_DEFUN([AC_ETHEREAL_ADD_DASH_L],
 [$1="$$1 -L$2"
 case "$host_os" in
   solaris*)
@@ -82,7 +82,7 @@ dnl Done by Guy Harris <guy@alum.mit.edu> on 1998-11-14.
 
 dnl ### Checks for structure members
 
-AC_DEFUN(AC_ETHEREAL_STRUCT_SA_LEN,
+AC_DEFUN([AC_ETHEREAL_STRUCT_SA_LEN],
 [AC_CACHE_CHECK([for sa_len in struct sockaddr], ac_cv_ethereal_struct_sa_len,
 [AC_TRY_COMPILE([#include <sys/types.h>
 #include <sys/socket.h>], [struct sockaddr s; s.sa_len;],
@@ -92,12 +92,55 @@ if test $ac_cv_ethereal_struct_sa_len = yes; then
 fi
 ])
 
+
+dnl
+dnl Check whether a given format can be used to print 64-bit integers
+dnl
+AC_DEFUN([AC_ETHEREAL_CHECK_64BIT_FORMAT],
+[
+  AC_MSG_CHECKING([whether %$1x can be used to format 64-bit integers])
+  AC_RUN_IFELSE(
+    [
+      AC_LANG_SOURCE(
+       [[
+#        ifdef HAVE_INTTYPES_H
+         #include <inttypes.h>
+#        endif
+         #include <glibconfig.h>
+         #include <stdio.h>
+         #include <sys/types.h>
+
+         main()
+         {
+           guint64 t = 1;
+           char strbuf[16+1];
+           sprintf(strbuf, "%016$1x", t << 32);
+           if (strcmp(strbuf, "0000000100000000") == 0)
+             exit(0);
+           else
+             exit(1);
+         }
+       ]])
+    ],
+    [
+      AC_DEFINE(PRId64, "$1d", [Format for printing 64-bit signed decimal numbers])
+      AC_DEFINE(PRIo64, "$1o", [Format for printing 64-bit unsigned octal numbers])
+      AC_DEFINE(PRIx64, "$1x", [Format for printing 64-bit unsigned hexadecimal numbers])
+      AC_DEFINE(PRIu64, "$1u", [Format for printing 64-bit unsigned decimal numbers])
+      AC_MSG_RESULT(yes)
+    ],
+    [
+      AC_MSG_RESULT(no)
+      $2
+    ])
+])
+
 #
 # AC_ETHEREAL_IPV6_STACK
 #
 # By Jun-ichiro "itojun" Hagino, <itojun@iijlab.net>
 #
-AC_DEFUN(AC_ETHEREAL_IPV6_STACK,
+AC_DEFUN([AC_ETHEREAL_IPV6_STACK],
 [
        v6type=unknown
        v6lib=none
@@ -208,7 +251,7 @@ yes
 # GNU Autoconf 2.13; the comment came from there.
 # Done by Guy Harris <guy@alum.mit.edu> on 2000-01-14. 
 #
-AC_DEFUN(AC_ETHEREAL_GETHOSTBY_LIB_CHECK,
+AC_DEFUN([AC_ETHEREAL_GETHOSTBY_LIB_CHECK],
 [
     # msh@cis.ufl.edu says -lnsl (and -lsocket) are needed for his 386/AT,
     # to get the SysV transport functions.
@@ -235,7 +278,7 @@ AC_DEFUN(AC_ETHEREAL_GETHOSTBY_LIB_CHECK,
 #
 # We use "connect" because that's what AC_PATH_XTRA did.
 #
-AC_DEFUN(AC_ETHEREAL_SOCKET_LIB_CHECK,
+AC_DEFUN([AC_ETHEREAL_SOCKET_LIB_CHECK],
 [
     # lieder@skyler.mavd.honeywell.com says without -lsocket,
     # socket/setsockopt and other routines are undefined under SCO ODT
@@ -253,7 +296,7 @@ AC_DEFUN(AC_ETHEREAL_SOCKET_LIB_CHECK,
 #
 # AC_ETHEREAL_PCAP_CHECK
 #
-AC_DEFUN(AC_ETHEREAL_PCAP_CHECK,
+AC_DEFUN([AC_ETHEREAL_PCAP_CHECK],
 [
        if test -z "$pcap_dir"
        then
@@ -275,7 +318,11 @@ AC_DEFUN(AC_ETHEREAL_PCAP_CHECK,
          #
          AC_MSG_CHECKING(for extraneous pcap header directories)
          found_pcap_dir=""
-         for pcap_dir in /usr/include/pcap $prefix/include/pcap $prefix/include /usr/local/include/pcap
+         pcap_dir_list="/usr/include/pcap $prefix/include/pcap $prefix/include"
+         if test "x$ac_cv_enable_usr_local" = "xyes" ; then
+           pcap_dir_list="$pcap_dir_list /usr/local/include/pcap"
+         fi
+         for pcap_dir in $pcap_dir_list
          do
            if test -d $pcap_dir ; then
                if test x$pcap_dir != x/usr/include -a x$pcap_dir != x/usr/local/include ; then
@@ -324,20 +371,36 @@ and did you also install that package?]]))
          [
            PCAP_LIBS=-lpcap
            AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
-         ], [AC_MSG_ERROR(Library libpcap not found.)],
-         $SOCKET_LIBS $NSL_LIBS)
+         ], [
+           AC_MSG_CHECKING([for pcap_open_live in -lpcap -lcfg -lodm])
+           ac_save_LIBS="$LIBS"
+           LIBS="-lpcap -lcfg -lodm"
+           AC_TRY_LINK(
+               [
+#      include <pcap.h>
+               ],
+               [
+       pcap_open_live(NULL, 0, 0, 0, NULL);
+               ],
+               [
+               AC_MSG_RESULT([yes])
+               PCAP_LIBS="-lpcap -lcfg -lodm"
+               AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
+               ],
+               [
+               AC_MSG_RESULT([no])
+               AC_MSG_ERROR([Library libpcap not found.])
+               ])
+           LIBS=$ac_save_LIBS
+         ], $SOCKET_LIBS $NSL_LIBS)
        AC_SUBST(PCAP_LIBS)
-])
 
-#
-# AC_ETHEREAL_PCAP_VERSION_CHECK
-#
-# Check whether "pcap_version" is defined by libpcap.
-#
-AC_DEFUN(AC_ETHEREAL_PCAP_VERSION_CHECK,
-[
-       AC_MSG_CHECKING(whether pcap_version is defined by libpcap)
+       #
+       # Check whether various variables and functions are defined by
+       # libpcap.
+       #
        ac_save_LIBS="$LIBS"
+       AC_MSG_CHECKING(whether pcap_version is defined by libpcap)
        LIBS="$PCAP_LIBS $SOCKET_LIBS $NSL_LIBS $LIBS"
        AC_TRY_LINK(
           [
@@ -350,19 +413,70 @@ AC_DEFUN(AC_ETHEREAL_PCAP_VERSION_CHECK,
           ac_cv_pcap_version_defined=yes,
           ac_cv_pcap_version_defined=no,
           [echo $ac_n "cross compiling; assumed OK... $ac_c"])
-       LIBS="$ac_save_LIBS"
        if test "$ac_cv_pcap_version_defined" = yes ; then
                AC_MSG_RESULT(yes)
                AC_DEFINE(HAVE_PCAP_VERSION, 1, [Define if libpcap version is known])
        else
                AC_MSG_RESULT(no)
        fi
+       AC_CHECK_FUNCS(pcap_open_dead)
+       #
+       # Later versions of Mac OS X 10.3[.x] ship a pcap.h that
+       # doesn't define pcap_if_t but ship an 0.8[.x] libpcap,
+       # so the library has "pcap_findalldevs()", but pcap.h
+       # doesn't define "pcap_if_t" so you can't actually *use*
+       # "pcap_findalldevs()".
+       #
+       # That even appears to be true of systems shipped with
+       # 10.3.4, so it doesn't appear only to be a case of
+       # Software Update not updating header files.
+       #
+       # (You can work around this by installing the 0.8 header
+       # files.)
+       #
+       AC_CACHE_CHECK([whether pcap_findalldevs is present and usable],
+         [ac_cv_func_pcap_findalldevs],
+         [
+           AC_LINK_IFELSE(
+             [
+               AC_LANG_SOURCE(
+                 [[
+                   #include <pcap.h>
+                   main()
+                   {
+                     pcap_if_t *devpointer;
+                     char errbuf[1];
+
+                     pcap_findalldevs(&devpointer, errbuf);
+                   }
+                 ]])
+             ],
+             [
+               ac_cv_func_pcap_findalldevs=yes
+             ],
+             [
+               ac_cv_func_pcap_findalldevs=no
+             ])
+         ])
+       #
+       # Don't check for other new routines that showed up after
+       # "pcap_findalldevs()" if we don't have a usable
+       # "pcap_findalldevs()", so we don't end up using them if the
+       # "pcap.h" is crufty and old and doesn't declare them.
+       #
+       if test $ac_cv_func_pcap_findalldevs = "yes" ; then
+         AC_DEFINE(HAVE_PCAP_FINDALLDEVS, 1,
+          [Define to 1 if you have the `pcap_findalldevs' function and a pcap.h that declares pcap_if_t.])
+         AC_CHECK_FUNCS(pcap_datalink_val_to_name pcap_datalink_name_to_val)
+         AC_CHECK_FUNCS(pcap_list_datalinks pcap_set_datalink pcap_lib_version)
+       fi
+       LIBS="$ac_save_LIBS"
 ])
 
 #
 # AC_ETHEREAL_ZLIB_CHECK
 #
-AC_DEFUN(AC_ETHEREAL_ZLIB_CHECK,
+AC_DEFUN([AC_ETHEREAL_ZLIB_CHECK],
 [
        if test "x$zlib_dir" != "x"
        then
@@ -380,7 +494,7 @@ AC_DEFUN(AC_ETHEREAL_ZLIB_CHECK,
          #
          ethereal_save_CFLAGS="$CFLAGS"
          CFLAGS="$CFLAGS -I$zlib_dir/include"
-         ethereal_save_CPPLAGS="$CPPLAGS"
+         ethereal_save_CPPFLAGS="$CPPFLAGS"
          CPPFLAGS="$CPPFLAGS -I$zlib_dir/include"
          ethereal_save_LIBS="$LIBS"
          AC_ETHEREAL_ADD_DASH_L(LIBS, $zlib_dir/lib)
@@ -473,7 +587,7 @@ AC_DEFUN(AC_ETHEREAL_ZLIB_CHECK,
                                # contains gzgets there.
                                #
                                CFLAGS="$ethereal_save_CFLAGS"
-                               CPPFLAGS="$ethereal_save_CPPLAGS"
+                               CPPFLAGS="$ethereal_save_CPPFLAGS"
                                LIBS="$ethereal_save_LIBS"
                        fi
                        want_zlib=no
@@ -513,10 +627,116 @@ AC_DEFUN(AC_ETHEREAL_ZLIB_CHECK,
        fi
 ])
 
+#
+# AC_ETHEREAL_LIBPCRE_CHECK
+#
+AC_DEFUN([AC_ETHEREAL_LIBPCRE_CHECK],
+[
+       if test "x$pcre_dir" != "x"
+       then
+         #
+         # The user specified a directory in which libpcre resides,
+         # so add the "include" subdirectory of that directory to
+         # the include file search path and the "lib" subdirectory
+         # of that directory to the library search path.
+         #
+         # XXX - if there's also a libpcre in a directory that's
+         # already in CFLAGS, CPPFLAGS, or LDFLAGS, this won't
+         # make us find the version in the specified directory,
+         # as the compiler and/or linker will search that other
+         # directory before it searches the specified directory.
+         #
+         ethereal_save_CFLAGS="$CFLAGS"
+         CFLAGS="$CFLAGS -I$pcre_dir/include"
+         ethereal_save_CPPFLAGS="$CPPFLAGS"
+         CPPFLAGS="$CPPFLAGS -I$pcre_dir/include"
+         ethereal_save_LIBS="$LIBS"
+         LIBS="$LIBS -lpcre"
+         ethereal_save_LDFLAGS="$LDFLAGS"
+         LDFLAGS="$LDFLAGS -L$pcre_dir/lib"
+       fi
+
+       #
+       # Make sure we have "pcre.h".  If we don't, it means we probably
+       # don't have libpcre, so don't use it.
+       #
+       AC_CHECK_HEADER(pcre.h,,
+         [
+           if test "x$pcre_dir" != "x"
+           then
+             #
+             # The user used "--with-pcre=" to specify a directory
+             # containing libpcre, but we didn't find the header file
+             # there; that either means they didn't specify the
+             # right directory or are confused about whether libpcre
+             # is, in fact, installed.  Report the error and give up.
+             #
+             AC_MSG_ERROR([libpcre header not found in directory specified in --with-pcre])
+           else
+             if test "x$want_pcre" = "xyes"
+             then
+               #
+               # The user tried to force us to use the library, but we
+               # couldn't find the header file; report an error.
+               #
+               AC_MSG_ERROR(Header file pcre.h not found.)
+             else
+               #
+               # We couldn't find the header file; don't use the
+               # library, as it's probably not present.
+               #
+               want_pcre=no
+             fi
+           fi
+         ])
+
+       if test "x$want_pcre" != "xno"
+       then
+               #
+               # Well, we at least have the pcre header file.
+               #
+               # We're only using standard functions from libpcre,
+               # so we don't need to perform extra checks.
+               #
+               AC_CHECK_LIB(pcre, pcre_compile,
+               [
+                       if test "x$pcre_dir" != "x"
+                       then
+                               #
+                               # Put the "-I" and "-L" flags for pcre at
+                               # the beginning of CFLAGS, CPPFLAGS,
+                               # LDFLAGS, and LIBS.
+                               #
+                               PCRE_LIBS="-L$pcre_dir/lib -lpcre $ethereal_save_LIBS"
+                       else
+                               PCRE_LIBS="-lpcre"
+                       fi
+                       AC_DEFINE(HAVE_LIBPCRE, 1, [Define to use libpcre library])
+               ],[
+                       if test "x$pcre_dir" != "x"
+                       then
+                               #
+                               # Restore the versions of CFLAGS, CPPFLAGS,
+                               # LDFLAGS, and LIBS before we added the
+                               # "--with-pcre=" directory, as we didn't
+                               # actually find pcre there.
+                               #
+                               CFLAGS="$ethereal_save_CFLAGS"
+                               CPPFLAGS="$ethereal_save_CPPFLAGS"
+                               LDFLAGS="$ethereal_save_LDFLAGS"
+                               LIBS="$ethereal_save_LIBS"
+                               PCRE_LIBS=""
+                       fi
+                       want_pcre=no
+               ])
+               AC_SUBST(PCRE_LIBS)
+       fi
+])
+
 #
 # AC_ETHEREAL_UCDSNMP_CHECK
 #
-AC_DEFUN(AC_ETHEREAL_UCDSNMP_CHECK,
+AC_DEFUN([AC_ETHEREAL_UCDSNMP_CHECK],
 [
        if test "x$ucdsnmp_dir" != "x"
        then
@@ -544,40 +764,84 @@ AC_DEFUN(AC_ETHEREAL_UCDSNMP_CHECK,
        AC_CHECK_HEADER(ucd-snmp/ucd-snmp-config.h,
        [
                #
-               # UCD SNMP may require "-lkstat" on Solaris, sigh.
-               # XXX - it may also require "-lcrypto" on some platforms;
-               # we should check for that as well, rather than requiring
-               # users to explicitly indicate whether it's required.
+               # UCD SNMP or Net-SNMP might require various helper
+               # libraries on various platforms, such as "-ldes425"
+               # in "/usr/kerberos/lib" on some versions of Red
+               # Hat Linux, or "-lkstat" on Solaris.
                #
-               AC_CHECK_LIB(snmp, sprint_realloc_objid,
-                 SNMP_LIBS=-lsnmp,
-                 [
-                   #
-                   # Throw away the cached "we didn't find it" answer.
-                   #
-                   unset ac_cv_lib_snmp_sprint_realloc_objid
-                   AC_CHECK_LIB(snmp, sprint_realloc_objid,
-                     [
-                       #
-                       # Throw away the cached "we found it" answer, so
-                       # that if we rerun "configure", we don't just blow
-                       # off this check and blithely assume that we don't
-                       # need "-lkstat".
-                       #
-                       # XXX - autoconf really needs a way to test for
-                       # a given routine in a given library *and* to test
-                       # whether additional "-L"/"-R"/whatever flags are
-                       # needed *before* the "-l" flag for the library
-                       # and to test whether additional libraries are
-                       # needed after the library *and* to cache all that
-                       # information.
-                       #
-                       unset ac_cv_lib_snmp_sprint_realloc_objid
-                       SNMP_LIBS="-lsnmp -lkstat"
-                     ],,$SOCKET_LIBS $NSL_LIBS $SSL_LIBS -lkstat
-                   )
-                 ], $SOCKET_LIBS $NSL_LIBS $SSL_LIBS
-               )
+               # It might also require "-lcrypto" on some platforms;
+               # if the user didn't specify --with-ssl, we check
+               # whether it would have made a difference and, if so,
+               # we tell the user that they needed to request it.
+               # (There are annoying licensing issues with it and
+               # GPL'ed code, so we don't include it by default.)
+               #
+               # XXX - autoconf really needs a way to test for
+               # a given routine in a given library *and* to test
+               # whether additional "-L"/"-R"/whatever flags are
+               # needed *before* the "-l" flag for the library
+               # and to test whether additional libraries are
+               # needed after the library *and* to cache all that
+               # information.
+               #
+               ethereal_save_LIBS="$LIBS"
+               found_sprint_realloc_objid=no
+               for extras in "" "-L/usr/kerberos/lib -ldes425" "-lkstat"
+               do
+                       LIBS="-lsnmp $extras $SOCKET_LIBS $NSL_LIBS $SSL_LIBS"
+                       if test -z "$extras"
+                       then
+                               AC_MSG_CHECKING([whether UCD SNMP includes sprint_realloc_objid])
+                       else
+                               AC_MSG_CHECKING([whether UCD SNMP includes sprint_realloc_objid (linking with $extras)])
+                       fi
+                       AC_TRY_LINK(
+                           [
+                           ],
+                           [
+                               sprint_realloc_objid();
+                           ],
+                           [
+                               #
+                               # We found "sprint_realloc_objid()",
+                               # and required the libraries in
+                               # extras as well.
+                               #
+                               AC_MSG_RESULT(yes)
+                               SNMP_LIBS="-lsnmp $extras"; break;
+                               found_sprint_realloc_objid=yes
+                               break
+                           ],
+                           [
+                               #
+                               # The link failed.  If they didn't ask
+                               # for SSL, try linking with -lcrypto
+                               # as well, and if *that* succeeds,
+                               # tell them they'll need to specify
+                               # --want-ssl.
+                               #
+                               AC_MSG_RESULT(no)
+                               if test "x$want_ssl" = "xno"
+                               then
+                                       LIBS="$LIBS -lcrypto"
+                                       AC_TRY_LINK(
+                                           [
+                                           ],
+                                           [
+                                               sprint_realloc_objid();
+                                           ],
+                                           [
+                                               #
+                                               # It worked with -lcrypto; tell
+                                               # them they'll need to specify
+                                               # --with-ssl.
+                                               #
+                                               AC_MSG_ERROR([UCD SNMP requires -lcrypto but --with-ssl not specified])
+                                           ])
+                               fi
+                           ])
+               done
+               LIBS="$ethereal_save_LIBS"
 
                #
                # If we didn't find "sprint_realloc_objid()", fail.
@@ -585,7 +849,7 @@ AC_DEFUN(AC_ETHEREAL_UCDSNMP_CHECK,
                # with "sprint_realloc_objid()", or they may need to
                # specify "--with-ssl".
                #
-               if test "$ac_cv_lib_snmp_sprint_realloc_objid" = no; then
+               if test "$found_snmp_sprint_realloc_objid" = no; then
                    AC_MSG_ERROR([UCD SNMP header files found, but sprint_realloc_objid not found in SNMP library.])
                fi
 
@@ -606,49 +870,11 @@ AC_DEFUN(AC_ETHEREAL_UCDSNMP_CHECK,
        ])
 ])
 
-#
-# AC_ETHEREAL_SSL_CHECK
-#
-AC_DEFUN(AC_ETHEREAL_SSL_CHECK,
-[
-       want_ssl=defaultyes
-
-       AC_ARG_WITH(ssl,
-       [  --with-ssl=DIR          use SSL crypto library, located in directory DIR.], [
-       if   test "x$withval" = "xno";  then
-               want_ssl=no
-       elif test "x$withval" = "xyes"; then
-               want_ssl=yes
-       elif test -d "$withval"; then
-               want_ssl=yes
-               AC_ETHEREAL_ADD_DASH_L(LDFLAGS, ${withval}/lib)
-       fi
-       ])
-
-       if test "x$want_ssl" = "xdefaultyes"; then
-               want_ssl=yes
-               withval=/usr/local/ssl
-               if test -d "$withval"; then
-                       AC_ETHEREAL_ADD_DASH_L(LDFLAGS, ${withval}/lib)
-               fi
-       fi
-
-       if test "x$want_ssl" = "xyes"; then
-               AC_CHECK_LIB(crypto, EVP_md5,
-                 [
-                   SSL_LIBS=-lcrypto
-                 ],,
-               )
-       else
-               AC_MSG_RESULT(not required)
-       fi
-])
-
 #
 # AC_ETHEREAL_RPM_CHECK
 # Looks for the rpm program, and checks to see if we can redefine "_topdir".
 #
-AC_DEFUN(AC_ETHEREAL_RPM_CHECK,
+AC_DEFUN([AC_ETHEREAL_RPM_CHECK],
 [
        AC_CHECK_PROG(ac_cv_ethereal_have_rpm, rpm, "yes", "no")
        if test "x$ac_cv_ethereal_have_rpm" = "xyes"; then
@@ -679,3 +905,278 @@ AC_DEFUN([AC_ETHEREAL_GNU_SED_CHECK],
                HAVE_GNU_SED=no
        fi
 ])
+
+#
+# AC_ETHEREAL_ADNS_CHECK
+#
+AC_DEFUN([AC_ETHEREAL_ADNS_CHECK],
+[
+       want_adns=defaultyes
+
+       AC_ARG_WITH(adns,
+changequote(<<, >>)dnl
+<<  --with-adns[=DIR]       use GNU ADNS (located in directory DIR, if supplied).   [default=yes, if present]>>,
+changequote([, ])dnl
+       [
+       if   test "x$withval" = "xno";  then
+               want_adns=no
+       elif test "x$withval" = "xyes"; then
+               want_adns=yes
+       elif test -d "$withval"; then
+               want_adns=yes
+               AC_ETHEREAL_ADD_DASH_L(LDFLAGS, ${withval}/lib)
+       fi
+       ])
+
+       if test "x$want_adns" = "xdefaultyes"; then
+               want_adns=yes
+               withval=/usr/local
+               if test -d "$withval"; then
+                       AC_ETHEREAL_ADD_DASH_L(LDFLAGS, ${withval}/lib)
+               fi
+       fi
+
+       if test "x$want_adns" = "xyes"; then
+               AC_CHECK_LIB(adns, adns_init,
+                 [
+                   ADNS_LIBS=-ladns
+               AC_DEFINE(HAVE_GNU_ADNS, 1, [Define to use GNU ADNS library])
+               have_good_adns=yes
+                 ],, $SOCKET_LIBS $NSL_LIBS
+               )
+       else
+               AC_MSG_RESULT(not required)
+       fi
+])
+
+
+#
+# AC_ETHEREAL_KRB5_CHECK
+#
+AC_DEFUN([AC_ETHEREAL_KRB5_CHECK],
+[
+       ethereal_save_CFLAGS="$CFLAGS"
+       ethereal_save_CPPFLAGS="$CPPFLAGS"
+       if test "x$krb5_dir" != "x"
+       then
+         #
+         # The user specified a directory in which kerberos resides,
+         # so add the "include" subdirectory of that directory to
+         # the include file search path and the "lib" subdirectory
+         # of that directory to the library search path.
+         #
+         # XXX - if there's also a kerberos in a directory that's
+         # already in CFLAGS, CPPFLAGS, or LDFLAGS, this won't
+         # make us find the version in the specified directory,
+         # as the compiler and/or linker will search that other
+         # directory before it searches the specified directory.
+         #
+         CFLAGS="$CFLAGS -I$krb5_dir/include"
+         CPPFLAGS="$CPPFLAGS -I$krb5_dir/include"
+         ac_heimdal_version=`grep heimdal $krb5_dir/include/krb5.h | head -n 1 | sed 's/^.*heimdal.*$/HEIMDAL/'`
+         ac_mit_version=`grep 'Massachusetts Institute of Technology' $krb5_dir/include/krb5.h | head -n 1 | sed 's/^.*Massachusetts Institute of Technology.*$/MIT/'`
+         ac_krb5_version="$ac_heimdal_version$ac_mit_version"
+         if test "x$ac_krb5_version" = "xHEIMDAL"
+             KRB5_LIBS="-L$krb5_dir/lib -lkrb5 -lasn1 $SSL_LIBS -lroken -lcrypt"
+         then
+             KRB5_LIBS="-L$krb5_dir/lib -lkrb5 -lk5crypto -lcom_err"
+         fi
+         if test "x$ac_krb5_version" = "xMIT"
+         then
+         AC_DEFINE(HAVE_MIT_KERBEROS, 1, [Define to use MIT kerberos])
+         fi
+       else
+         AC_PATH_PROG(KRB5_CONFIG, krb5-config) 
+         if test -x "$KRB5_CONFIG"
+         then
+           KRB5_FLAGS=`"$KRB5_CONFIG" --cflags`
+           KRB5_LIBS=`"$KRB5_CONFIG" --libs`
+           CFLAGS="$CFLAGS $KRB5_FLAGS"
+           CPPFLAGS="$CPPFLAGS $KRB5_FLAGS"
+           #
+           # If -lcrypto is in KRB5_FLAGS, we require it to build
+           # with Heimdal/MIT.  We don't want to built with it by
+           # default, due to annoying license incompatibilities
+           # between the OpenSSL license and the GPL, so:
+           #
+           #   if SSL_LIBS is set to a non-empty string, we
+           #   remove -lcrypto from KRB5_LIBS and replace
+           #   it with SSL_LIBS;
+           #
+           #   if SSL_LIBS is not set to a non-empty string
+           #   we fail with an appropriate error message.
+           #
+           case "$KRB5_LIBS" in
+           *-lcrypto*)
+               if test ! -z "$SSL_LIBS"
+               then
+                   KRB5_LIBS=`echo $KRB5_LIBS | sed 's/-lcrypto//'`
+                   KRB5_LIBS="$KRB5_LIBS $SSL_LIBS"
+               else
+                   AC_MSG_ERROR([Kerberos library requires -lcrypto but --with-ssl not specified])
+               fi
+               ;;
+           esac
+           ac_krb5_version=`"$KRB5_CONFIG" --version | head -n 1 | sed -e 's/^.*heimdal.*$/HEIMDAL/' -e 's/^Kerberos .*$/MIT/'`
+         fi
+       fi
+
+       #
+       # Make sure we have "krb5.h".  If we don't, it means we probably
+       # don't have kerberos, so don't use it.
+       #
+       AC_CHECK_HEADER(krb5.h,,
+         [
+           if test "x$krb5_dir" != "x"
+           then
+             #
+             # The user used "--with-krb5=" to specify a directory
+             # containing kerberos, but we didn't find the header file
+             # there; that either means they didn't specify the
+             # right directory or are confused about whether kerberos
+             # is, in fact, installed.  Report the error and give up.
+             #
+             AC_MSG_ERROR([kerberos header not found in directory specified in --with-krb5])
+           else
+             if test "x$want_krb5" = "xyes"
+             then
+               #
+               # The user tried to force us to use the library, but we
+               # couldn't find the header file; report an error.
+               #
+               AC_MSG_ERROR(Header file krb5.h not found.)
+             else
+               #
+               # We couldn't find the header file; don't use the
+               # library, as it's probably not present.
+               #
+               want_krb5=no
+               AC_MSG_RESULT(No Heimdal or MIT header found - disabling dissection for some kerberos data in packet decoding)
+             fi
+           fi
+         ])
+
+       if test "x$want_krb5" != "xno"
+       then
+           #
+           # Well, we at least have the krb5 header file.
+           # Check whether this is Heimdal or MIT.
+           #
+           AC_MSG_CHECKING(whether the Kerberos library is Heimdal or MIT)
+           if test "x$ac_krb5_version" = "xHEIMDAL" -o "x$ac_krb5_version" = "xMIT"
+           then
+               #
+               # Yes.
+               # Check whether we have krb5_kt_resolve - and whether
+               # we need to link with -lresolv when linking with
+               # the Kerberos library.
+               #
+               AC_MSG_RESULT($ac_krb5_version)
+               ethereal_save_LIBS="$LIBS"
+               found_krb5_kt_resolve=no
+               for extras in "" "-lresolv"
+               do
+                   LIBS="$KRB5_LIBS $extras"
+                   if test -z "$extras"
+                   then
+                       AC_MSG_CHECKING([whether $ac_krb5_version includes krb5_kt_resolve])
+                   else
+                       AC_MSG_CHECKING([whether $ac_krb5_version includes krb5_kt_resolve (linking with $extras)])
+                   fi
+                   AC_TRY_LINK(
+                       [
+                       ],
+                       [
+                           krb5_kt_resolve();
+                       ],
+                       [
+                           #
+                           # We found "krb5_kt_resolve()", and required
+                           # the libraries in extras as well.
+                           #
+                           AC_MSG_RESULT(yes)
+                           KRB5_LIBS="$LIBS"
+                           AC_DEFINE(HAVE_KERBEROS, 1, [Define to use kerberos])
+                           if test "x$ac_krb5_version" = "xHEIMDAL"
+                           then
+                               AC_DEFINE(HAVE_HEIMDAL_KERBEROS, 1, [Define to use heimdal kerberos])
+                           fi
+                           if test "x$ac_krb5_version" = "xMIT"
+                           then
+                               AC_DEFINE(HAVE_MIT_KERBEROS, 1, [Define to use MIT kerberos])
+                           fi
+                           found_krb5_kt_resolve=yes
+                           break
+                       ],
+                       [
+                           AC_MSG_RESULT(no)
+                       ])
+               done
+               if test "$found_krb5_kt_resolve" = no
+               then
+                   #
+                   # We didn't find "krb5_kt_resolve()" in the
+                   # Kerberos library, even when we tried linking
+                   # with -lresolv; we can't link with kerberos.
+                   #
+                   if test "x$want_krb5" = "xyes"
+                   then
+                       #
+                       # The user tried to force us to use the library,
+                       # but we can't do so; report an error.
+                       #
+                       AC_MSG_ERROR(Usable $ac_krb5_version not found)
+                   else
+                       #
+                       # Restore the versions of CFLAGS and CPPFLAGS
+                       # from before we added the flags for Kerberos.
+                       #
+                       AC_MSG_RESULT(Usable $ac_krb5_version not found - disabling dissection for some kerberos data in packet decoding)
+                       CFLAGS="$ethereal_save_CFLAGS"
+                       CPPFLAGS="$ethereal_save_CPPFLAGS"
+                       KRB5_LIBS=""
+                       want_krb5=no
+                   fi
+               fi
+               LIBS="$ethereal_save_LIBS"
+           else
+               #
+               # It's not Heimdal or MIT.
+               #
+               AC_MSG_RESULT(no)
+               if test "x$want_krb5" = "xyes"
+               then
+                   #
+                   # The user tried to force us to use the library,
+                   # but we can't do so; report an error.
+                   #
+                   AC_MSG_ERROR(Kerberos not found)
+               else
+                   #
+                   # Restore the versions of CFLAGS and CPPFLAGS
+                   # from before we added the flags for Kerberos.
+                   #
+                   AC_MSG_RESULT(Kerberos not found - disabling dissection for some kerberos data in packet decoding)
+                   CFLAGS="$ethereal_save_CFLAGS"
+                   CPPFLAGS="$ethereal_save_CPPFLAGS"
+                   KRB5_LIBS=""
+                   want_krb5=no
+               fi
+           fi
+       else
+           #
+           # The user asked us not to use Kerberos, or they didn't
+           # say whether they wanted us to use it but we found
+           # that we couldn't.
+           #
+           # Restore the versions of CFLAGS and CPPFLAGS
+           # from before we added the flags for Kerberos.
+           #
+           CFLAGS="$ethereal_save_CFLAGS"
+           CPPFLAGS="$ethereal_save_CPPFLAGS"
+           KRB5_LIBS=""
+           want_krb5=no
+       fi
+       AC_SUBST(KRB5_LIBS)
+])
+