+dnl the order in which libraries is checked is important
+dnl eg. adns on Solaris 2.5.1 depends on -lnsl and -lsocket
+AC_CHECK_LIB(gmp,mpz_init_set_str)
+AC_CHECK_LIB(gmp2,mpz_init_set_str)
+AC_CHECK_LIB(gmp,__gmpz_init_set_str)
+REQUIRE_HEADER([gmp.h])
+dnl Would love to barf if no gmp was found, but how to test? Requiring the header will do for now.
+SECNET_C_GETFUNC(inet_ntoa,nsl)
+AC_CHECK_LIB(socket,socket)
+SECNET_C_GETFUNC(inet_aton,resolv)
+AC_CHECK_LIB(adns,adns_init)
+REQUIRE_HEADER([adns.h])
+
+AC_MSG_NOTICE([Checking requirements for IPv6 support...])
+enable_ipv6=true
+m4_define(NO_IPV6,[enable_ipv6=false])
+AC_CHECK_DECL(AF_INET6, [],[NO_IPV6],[#include <netinet/in.h>])
+AC_CHECK_FUNC(adns_addr2text, [],[NO_IPV6])
+if $enable_ipv6; then
+ AC_MSG_NOTICE([Enabling IPv6 support])
+ AC_DEFINE(CONFIG_IPV6, 1,
+ [Define to 1 to use IPv6 support in system and adns])
+else
+ AC_MSG_WARN([Disabling IPv6 support])
+fi
+
+SUBDIRMK_MAKEFILES(common.make)
+
+AC_OUTPUT(,
+ echo timestamp >config.stamp)
+
+AH_TOP([
+#ifndef _CONFIG_H
+#define _CONFIG_H
+])
+
+AH_BOTTOM([
+/* -*- c -*- */
+
+/* These used to be in config.h.bot, but are now in configure.in. */
+
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#else
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#else
+#if SIZEOF_UNSIGNED_LONG_LONG==8
+typedef unsigned long long uint64_t;
+typedef long long int64_t;
+#elif SIZEOF_UNSIGNED_LONG==8
+typedef unsigned long uint64_t;
+typedef long int64_t;
+#else
+#error I do not know what to use for a uint64_t.
+#endif
+
+/* Give us an unsigned 32-bit data type. */
+#if SIZEOF_UNSIGNED_LONG==4
+typedef unsigned long uint32_t;
+typedef long int32_t;
+#elif SIZEOF_UNSIGNED_INT==4
+typedef unsigned int uint32_t;
+typedef int int32_t;
+#else
+#error I do not know what to use for a uint32_t.
+#endif
+
+/* An unsigned 16-bit data type. */
+#if SIZEOF_UNSIGNED_INT==2
+typedef unsigned int uint16_t;
+typedef int int16_t;
+#elif SIZEOF_UNSIGNED_SHORT==2
+typedef unsigned short uint16_t;
+typedef short int16_t;
+#else
+#error I do not know what to use for a uint16_t.
+#endif